I've never had this with my other DC.
Dd has only just turned 8.
She is a very active child and does many hours of physical activity and is coached 15 hours plus.
I've already noticed hips and breast buds appearing and a feint bit of public hair 
About a month ago we were snuggling and I caught a whiff of her armpits and the smell was really pungent. She showers reluctantly every day and I bought her a deodorant of her own just thinking it was earlier than the others but she'd get on with it like they did .
She was so upset and said I had humiliated her, called her smelly (I hadn't )
I left it a week then Dh (who notices NOTHING) said her body odour was bad.
I gently persuaded her to give the deodorant a go after her next shower and she went into meltdown again. I'm starting to wonder if I should just apply t whilst she sleeps.
I've very aware of school and how nasty children can be and Is be so devastated for her if she had a hard time for this reason at school which is so easy(?) to fix.