1. Oh, look! His eyes are all cross-eyed!
Listen, this new baby is perfect, there is nothing wrong with him whatsoever. His poo doesn't even smell. Got it? Woe betide any innocent remark that suggests there's something peculiar or unattractive about her newborn.
Secretly, she's worrying the baby will never have unwonky eyes even though the health visitor says it's normal at this age. But that's her business. Same goes for any comments about their 'silly botty', 'chubby chops' or 'funny smile'.
2. Have you considered letting her cry it out?
She hasn't put her down yet so forget it if you think the baby 'needs' to settle herself. The baby's only just been born, for goodness sake!
Yes, you might have reached that point of frustration, when you barricaded yourself in the downstairs loo wearing noise-cancelling headphones while your other half attempted controlled crying. But remember you broke free and rugby-tackled him to the ground in the landing and accused him of neglecting your baby? New mum might try it but she needs to come to her own decision in her own time.
3. You'll never have a decent night's sleep ever again.
Wholly unsupportive and mean to voice this she is only getting 45 minutes a time. Just look at her: she's grey, dishevelled and exhausted. Tell her the day will come when her little one sleeps for 12 hours a night - just don't tell her that when it happens a) she'll be poking the baby awake to check she's still alive or b) the little one might be a teenager. It will buoy her up when she is sinking not swimming.
4. What's that funny rash on his body?
Every new mum is paranoid about the sprinkle of spots which have just popped up on her baby's tummy. We all know those patchy splodges come as quickly as they go.
But it wasn't so long ago you were doing the glass test yourself on what ended up being a bit of your mother-in-law's lipstick. It's not wrong to point out a blemish - after all, babies get ill very quickly. Just don't do it as if you're auditioning for a part in a soap opera. Keep it calm.
5. If you think it's hard now...
Pointing out kids become more complex as they grow up is not helpful. Better to suggest things change rather than worsen. And at least you get to deal with your children's issues on a decent night's sleep. Wasn't it you who said 'I can deal with anything as long as he sleeps'?
6. I was like you on my first but I didn't make the same mistakes on my second.
Talk about patronising! She's doing her best and she'll find her way. Hey, she might even be doing it right. If you really do think you have a great tip, then wait until she isn't flapping because she's just been covered in an arc of sick.
7. Did you see Kate Middleton the other day?
Give over - she will recall that conversation she had with you when she was pregnant about starting sit-ups three days after the birth. She understands now. Don't rub her nose in it with Kate's amazing tummy. And don't buy her celeb mags either.
8. I'd love a cuppa.
She's got her hands full. Stick the kettle on yourself instead and make her one while you're at it.
9. Isn't he sleeping through yet?
Quite possibly the most undermining thing you can say to a new mum. You're suggesting the baby is not performing as it should and she's doing something wrong. If yours did, lucky you. But don't tell her!
10. Don't worry!
This is asking the impossible. She is programmed now to see danger everywhere and assume the worst. The best thing you can do is help her talk through her worries and then she might realise her request for everyone to wear a germ mask when they enter the house is a bit OTT.
11. Did you see that study that says whatever you're doing with your child, it's wrong?
If she intends to go back to work, do not bring up the headlines claiming nursery is damaging for babies. If she's staying at home, do not mention the story reporting early socialisation is key to achievement in later life. She's already wondering if that night on the tiles before she knew she was pregnant is responsible for her baby's wonky eyes.
12. I'm so tired.
Of course you are. Life gets more demanding as we adapt to school runs and work. And, yes, you've been through it just like her. But at least you haven't recently seen 2am. Or 3am. Or 4am.
She wins. Hands down.