She has found that the "teen talk", whether it be about periods, spots or hormones, should be part of an ongoing conversation rather than a separate, serious chat.
"Right from when Maddie was tiny, even when she was a toddler, when I had my period she would be in the bathroom with me," Sawalha told The Huffington Post UK.
"I would explain what I was doing and explain about sanitary towels right from that age."
"It's always been part of her life," Sawalha continued.
"In fact, when her period started, I was in the bath and she sat on the loo and she said: 'Oh my period's started'."
Sawalha, who is also mum to Kiki, nine, said because there was no "big announcement" about periods, Maddie felt less anxious about discussing it.
"It was really nice," she added. "We went off to Boots and walked round the aisles to find some products to get.
"She ended up choosing Always (which she swears by). I just wanted to make sure she was comfortable."
Sawalha said aside from periods, she is also experiencing Maddie dealing with spots, hormones, mood swings and even the effects of social media.
The 'Loose Women' presenter said she's slowly realised sometimes the best way to help a teenager is to give them a bit of space.
"I have always talked to Maddie about her feelings, her feelings are valid, whatever they are," she explained.
"But if she is looking a bit classic moody teenager, I will not go into: 'Right, what's going on here and what's that on your face Maddam?'
"All that will get is conflict, so I try to think about what's going on and let her have her time alone."
Sawalha said when it comes to dealing with changes in her daughter's body and skin, she makes it clear she understands what Maddie is going through.
"Some days she has spots and I can see and feel that she's really bothered," she said.
"I won't dismiss it and say 'Oh don't worry, it's fine', I'll take action and work on it together with her, whether it's going up to help her cleanse her face or giving her a hug and telling her I know how she feels.
"Validating her feelings, rather than dismissing them, is a better approach."
Whatever issues teenagers are facing, Sawalha said she believes it's important for parents to try to ensure they don't make the conversations too "daunting" for kids.
"I come very much from the school of thought that the conversations should be ongoing, not unexpected," she said.
"You don't think: 'Right now I'm going to sit down and have this teen talk and in this talk we are going to go through x y z', I think that's too daunting.
"Not only for you but for the child, because if you're going to slot into a completely different way of talking to them it will be very odd."
Sawalha shared her advice for parents on how to discuss puberty with your kids.
Allow a two-way conversation.
"I did something wrong a couple of weeks ago," Sawalha admitted when explaining why it's important for parents to listen to their teenagers as well as talk to them.
"I said something about sleepovers in front of her friends that she said was really 'uncomfortable'. She told me she felt awkward and I had no idea.
"I listened to her and now I won't do it again."
Make sure the conversations aren't just for mums.
Any puberty talk, whether it's between sons or daughters and their parents, shouldn't be restricted to mums.
"My husband is incredibly open and has also had that ongoing conversation with Maddie," she said.
"The other day she was in the car and forgot her sanitary towels and she shouted: 'Dad, dad, can you go in and get my sanitary towels!"
"He will go and buy them for her too. It's a different world now, dads are so much more open than they would have been when I was growing up, she has no problem talking about it in front of her dad."
Admit you feel nervous, if you feel nervous.
Sawalha said one of her biggest pieces of advice for parents would be to talk to their child, whatever the issue, with complete honesty.
"It is so hard for parents," she explained. "Just take it step-by-step if you haven't always been open with them - you don't have to talk about everything in one great big conversation.
"Just say: 'I feel nervous' if you do feel nervous, or 'I feel a bit awkward' and ask them if they do too."
Sawalha said parents don't need to pretend they "know everything" and are always confident, because kids can pick up on when they're faking it.
Don't 'over-talk' things.
Sawalha said sometimes parents may talk too much about aspects of puberty, sex and relationships that kids aren't ready for.
"Try not to over-talk things," she advised. "Sometimes you can go further than they're ready for.
"You have to be open to maybe getting it wrong sometimes, I have over-talked stuff and said: 'Well what's the matter, are you sure nothing is the matter, is it this, is it that?'
"It just hormones, so it's about really listening, looking at her, noticing the signs.
"The same with sex - don't over-talk it, if they ask a question just answer that question don't go on for ten more because they'll let you know when they want to deal with stuff."
Admit it's a tough time for both of you.
Just as teenagers are going through puberty and experiencing changes, Sawalha said it's easy to forget it's hard for parents, too, to watch their kids grow up.
"There is that bit of grief when your child is slowly growing away from you," she explained.
"You can't fix things anymore with a cuddle and a Disney film - things are more complicated.
"A very wise person said to me once, every child is there to teach us something about ourselves and I think if you think of it as a two street where I'm learning from her and she's learning from me, it can be a really positive experience rather than a battlefield."
For those parents who have put off having conversations about puberty, Sawalha said there's no need to worry.
"Keep going at it," she added. "There are so many challenges and new challenges for parents of teens, but it is never ever too late to start the conversation."
Nadia Sawalha and her daughter Maddie joined Boots and P&G's #TeenTalk campaign to provide parents and teens with the tools and tips they need. They've put together a guide to help teens comfortably through puberty.