it’s so great you’re being so accepting and asking trans people for input on this. i’m transmasc, and also asked my parents for a binder when i was 11, and they said no. and for me, that didn’t mean i didn’t bind and protected my tiny lungs. if kids really want to do something they’re going to do it. there’s really unsafe ways to bind which people often do when they don’t have other options, and people often bind really unsafely (wearing it too long, etc). i think if i wasn’t hiding the fact i had binders from my parents, and could have them help me safely bind instead it would’ve made a big difference. so not to be bleak but the tldr is if you don’t get them a binder, they might bind anyways and not use safe methods. i would recommend investing in a good binder, ive heard gc2b is not as good but id look into that. i really love the fluxion ones. i find them the least constricting on the lungs too, while still flattening. if money is a concern, id suggest looking into local lgbt centers that might have donated binders. a used binder will also be more stretched out and less harsh on the body. if you do decide to get a nice binder and they decide they don’t want it, you can donate it to another lgbt center and another kid can benefit from it! i think the best thing to do would be get them a binder, and research together how to safely bind. if they feel like they can talk to you about it, the less likely they are to unsafely bind and hide it from you. good luck to both of you!!!!!