Adults buying kids' trainers? Reebok specifically... Experiences?

[Bettyhatesavocados]

Question for my mum, really. She loves Reebok Classics and always buys the adult size. She has very small feet (EU 36). I told her she should buy the kids' size as they are considerably cheaper. The UK 3.5 in adult version has the exact same measurements as the UK 4 in the kid version according to the size guide. When she called to check there was no difference, Reebok CS said the 'cut' was different, and the adviser advised buying the adult shoe.
If you have small feet, have you ever bought the kids' size (esp Reebok) and found they are much narrower or anything? My mum has narrow(ish) feet but a bunion - affectionately nicknamed Spud - on one foot that needs to be accommodated.
I'm not sure whether the adviser was not so knowledgeable or there really is a difference? I'm not sure what was meant by 'different cut' ... I mean, surely feet are feet whether on a teen or an adult. She's on a budget and buying the kids' size would save £20, so not to be sniffed at.
Thanks.

I get the size 5 boys Reebok classics.

DM used to get DS’s hand me down trainers, she was gutted when his feet got bigger than hers!

Reebok classic kids are a lot narrower than the adults, you need to size up. I'm a 4 and in classics a 5. The arch support felt wrong too.
She should try them on, they might be fine.

Best thing about having diddy feet is cheaper shoes! I've never had any problems.

Well, this has never occurred to me and my size 4.5 feet! Will definitely check out the kids range for my next pair of trainers. It will make up for having sons with stupidly big feet.

I’m a size 4 so often buy from the children’s section. I’ve got the same pair of trainers (Nike air max 90) in children and adult sizes. The adult pair is a 4 and the child ones are a 4.5. I always have to go up half a size if they’re children’s ones. They also aren’t as hard wearing or bouncy. Despite them being the same style, the adult pair is far superior.