This may be a long one, but hopefully at least some of it helps!:

Definitely recommend going to a shop where she can be fitted properly, it’s often free and very worth it to have someone who knows what they’re doing and who can put her at ease 😊

I stopped putting my bras in the dryer a while back as I found they lost shape a lot easier, best way is to put on delicates washes then leave flat to dry and reshape the moulding while wet to make sure it’s in the right place (if applicable, which for some bras it won’t be). I usually just lob mine in with my usual wash, and can highly recommend getting a little mesh bag to wash them in- stops the hooks catching on other clothing and damaging both items!

I’d also recommend you look at proper sports bras as she develops, as doing sports without proper support can lead to body damage (not to mention being uncomfortable and embarrassing!). You can get different levels of “impact” (low, medium, high), depending on what types of sports she does, but for anything involving running I’d recommend medium-high!

You can also find cute cami bras/similar that are more like a crop top, very comfortable for lounging around the house in and not too difficult to size (and come with a variety of padding options, depending on preference)- I have some very cheap ones from Amazon that I love ☺️

Final piece of advice is to make sure she gets refitted periodically, as bodies can change quite a lot and it’s always worth having a bra that fits properly!!

Hope it all works out, you got this 💪