Young Emma picked up the phone after finding her heavily-pregnant mum Catherine Bazzard, 27, unconscious at the bottom of the stairs.
She dialled 999 and calmly gave her address and told the operator her mum had fallen down the stairs with "a baby in her tummy".
She stayed on the line for 11 minutes, explained her mum had banged her head but was not bleeding and said she had even checked the door was unlocked ready for an ambulance crew.
In the heart-warming recording (see below for the full transcript) the caring youngster is heard telling call handler Sarah Morris: "Mummy fall down a stairs and she has got a baby."
When Morris asked whether the baby is "asleep" and how old it is, Emma said: "It's in mummy's tummy. It's very, very big. It's coming at Christmas."
Thanks to Emma's remarkable actions paramedics arrived within minutes at the house in Nailsea, Somerset and Catherine was rushed to hospital.
Young Emma visited her local ambulance station on 23 December to be awarded a bravery certificate.
Morris, who Emma spoke to on the phone, said: "When I first spoke to the little girl I knew that she was young, but was amazed to discover that she was only three.
"The amount of detail she was able to provide was incredible; she answered every question I put to her more calmly than most adults under similar circumstances."
Paramedic Michelle Foster, who has worked for the ambulance service for seven years and responded to Emma's 999 call, said she was amazed by the little girl's response.
She said: "When we arrived, the door was already open ready for us. Emma was so relieved to see us, she was very distressed.
"We needed to take Catherine to hospital quickly because she hadn't felt the baby move and we were concerned about both of them and worried she had landed on her tummy."
Bazzard had tumbled down the stairs as rushed to pick her five-year-old son Harry up from school. She landed at the bottom, rupturing her placenta and was given an injection to stop internal bleeding.
She stayed in hospital for three nights before being allowed home but had to be rushed back two days later because she was still bleeding heavily, and stayed in for ten more nights.
Bazzard said: "I remember falling down the stairs and Emma bringing me the phone. She couldn't get the 'nine' button to work on the phone so I pressed it for her.
"The rest of it I heard through listening to the audio and hearing how amazing she was. I was so emotional when I first heard the call. I cried a lot.
"We couldn't imagine at all that she'd know what to do. We didn't explicitly teach her.
"We have explained what to do to Harry before. She must have just listened and managed to copy what we told him. I can't express enough how proud we are.
"The confidence which she said everything with on the phone just amazed us.
"If I had phoned an ambulance in the same situation there is no way I couldn't handled it as calmly as she did."
Bazzard said had Emma not responded so quickly her son George would have been born dangerously early.
She said: "It could have been really serious. When I regained consciousness I couldn't feel George kicking.
"For the whole of the ambulance ride, the thought that something might have happened to him was going through my head.
"I had hit my placenta which ruptured and cause quite a deal of distress.
"Had Emma not responded as quickly as she did, they wouldn't have been able to give me the injection and George would have been seven weeks premature, which in itself is not good."
George, who is now three weeks old, was born on 4 December, four weeks prematurely.
Bazzard added: "Luckily, it hasn't had any impact on him whatsoever. He is happy and healthy.
"I'm very proud of what Emma did - proud, emotional and absolutely amazed.
"There is no way we thought she was capable of doing what she did."
Catherine and husband Ben Bazzard, 33, who teaches at a local school, said children should be taught how to respond in emergencies by their parents and in lessons.
South West Ambulance Service has agreed to send ambulances to Emma's pre-school to raise awareness among the young children there.
Call handler Sarah Morris: "Ambulance service, tell me exactly what has happened."
Three-year-old Emma: "Erm....."
E: "Mummy fall down a stairs."
S: "Your mummy fell down the stairs?"
E: "And she got a baby."
S: "And she has got a baby?"
S: "Was she holding the baby when she fell darling?"
S: "Alright. How old is your mummy?"
E: "Erm, how old are you mummy? How old are you? How old are you mummy?"
S: "Don't worry darling. Did mummy fall down the stairs holding the baby?"
S: "Do you know your address?"
E: [Emma gives her address].
S: "I've got that in Nailsea. Is that right? Do you live in Nailsea?"
S: "What's your name?"
S: "How old are you Emma?"
S: "You're three. Ok, my name is Sarah and we are going to help your mummy, ok?"
S: "Did mummy and baby fall down the stairs at the same time?"
S: "Ok lovely. When did that happen?"
E: "In the house she fall down a stairs."
S: "Did that just happen?"
S: "Are mummy and the baby awake?"
E: "Mummy, mummy, erm, yeah.
S: "Are mummy's eyes open?"
E: "Mummy is asleep."
S: "Is the baby asleep?"
E: "I don't know."
S: "Is baby awake?"
E: "I think....."
S: "Is mummy asleep?"
S: "Alright my darling we're going to help mummy, ok? Go up to your mummy for me."
E: "I'm already with her."
S: "Ok, is she breathing?"
S: "Mummy's breathing is she?"
E: "Ah, yeah."
S: "Ok darling, bear with me a second. Stay on the phone - I'm not going to hang up the phone."
S: "You need to stay on the phone with me. Is the baby a boy or a girl?"
E: "A boy."
S: "A baby boy, ok. Alright my darling wait a second. What happened to make mummy fall down?"
E: "I don't know. Just fall down."
S: "Is mummy still asleep?"
E: "She's waking up now."
S: "Tell mummy to stay still."
E: [to her mum] "Still mummy."
S: "Tell mummy to stay still."
E: "I did."
S: "Well done ok. Is mummy bleeding?"
S: "Is the baby bleeding?"
E: "I don't know."
S: "What's the baby called?"
E: "We don't know yet."
S: "Where is mummy hurt?"
E: [to her mum] where are you hurt? Mummy's head is hurt."
S: "Ok. Stay on the phone. Tell mummy to stay still. How old is the baby?"
E: "It's in mummy's tummy."
S: "The baby is in mummy's tummy. Ah, ok darling, that's ok. How is mummy doing? Is she still awake?"
E: "Yeah. "
S: "Ok my darling. Ok, well done. Hold on a second. Is mummy hurt anywhere else?"
E: [to mum] Are you hurt anywhere else mummy? Are you hurt anywhere else? [to Sarah] No."
S: "Is mummy awake and talking to you?"
E: "She has gone back to sleep now."
S: "Ok. The ambulance is coming my lovely so I'm going to stay on the phone with you. Is your door open?"
S: "Is it locked?"
E: [to her mum] Is the door locked? [to Sarah] "No."
S: "So we can open it can we?"
S: "Ok, you need to stay on the phone with me. You need to watch your mummy, and make sure that mummy's breathing ok? Do you know what that means?"
S: "Good girl. You're a superstar. Just keep looking at mummy and let me know is she is awake or not."
E: "I'm with mummy."
S: "That's ok darling. You try and talk to mummy. Is mummy talking?"
S: "How big is mummy's tummy Emma? Is baby big in mummy's tummy?"
E: "It's very, very big."
S: "Alright poppet. That's good. You're going to be a big sister are you?"
E: "He is coming at Christmas."
S: "Tell your mummy to keep still and the ambulance is coming."
E: [to mum] "The ambulance is coming."
S: "You are such a clever girl. Talk to mummy and tell her everything is ok."
E: [to mum] "Everything ok."
S: "Emma you are a superstar. Your mummy is going to be very proud of you. What's mummy doing now?"
E: "I'm giving mummy a cuddle."
S: "You're giving mummy a cuddle? Good girl. Well done my poppet. And is mummy bleeding at all?"
S: "She just banged her head?"
S: "You sit next to her. You hold her hand for me, ok?"
S: "Good girl. Well done Emma. You are such a clever girl. Is mummy at the bottom of the stairs? Did she go all the way down the stairs?"
S: "Oh dear. Was that a bit scary?"
E: "Erm yeah it was. It was a bit scary."
S: "I bet it was a bit scary, but we are going to come and help mummy. You are so clever to ring up, aren't you?"
E: "Mummy said '999' and I did it."
[The pair talk about how 'clever' Emma is.]
S: "Did mummy bang her tummy?"
E: [to mum] Did you bang your tummy mummy? [to Sarah] I don't think so."
[Emma continues to talk to Sarah about how she is holding her mummy's hand and staying with her.]
E: "Mummy's back hurts."
S: "Ok darling, when the ambulance get there we'll be able to give her something to make her feel better. Ok? Just make sure that mummy has her eyes open and is awake ok?"
E: [to mum] "Make sure you have your eyes open."
S: "That's good. If mummy goes back to sleep you need to tell me. Ok?"
S: "So is mummy going to have a baby boy or a baby girl?"
E: "A boy."
S: "So you're going to have a brother? That's exciting."
E: "I'm going to have two brothers!"
S: "You already have a brother?"
E: "Yeah but he's at school."
S: "So you're going to have two brothers?"
S: "Is that what Santa is going to bring you, a baby brother?"
E: "No it's in mummy's tummy! Santa isn't bringing it."
S: "Can you hear the ambulance yet Emma?"
E: "I can hear it."
S: "Ok, you let me know when you can see them ok? You're so clever. Is mummy's eyes open?"
S: "You let me know when you can see the ambulance."
E: "They're here."
S: "Can you open the door Emma?"
S: "Stay on the phone Emma. Don't hang the phone up. Talk to me while you open the door, so I know the door is open."
E: "I'm not. The door is open."
S: "Good girl. Well done. Can you see the men in the green suits yet?"
E: "Yes they are here."
S: "Are they coming in the house?"
Paramedic: "Yes we're here. We're in."
S: "Good well done Emma you're a clever girl. I'm going to leave you there ok? Good girl sweetheart. You're very clever. Bye bye."