Is it twin blocks? The more she wears them the quicker that phase is over. They try to time using them while a growth spurt is happening to avoid prolonging it. Ds took his out to eat but otherwise wore them full time.
My dd was the first to get them n her friend group but they are becoming more commonly used.She took them out for eating but managed to keep them in the rest of the time.I think she was spurred on after her first after appointment when her teeth had moved so much. She had to widen the top brace too but managed it all with just the promise of some Ben and Jerry's after each visit to ease any pain(which she never got). We are out the other side now,fixed braces off. I think she had to want to do it,even if she just wore them at home and night that would be better and maybe if that meant she had a measurable change in her bite it would encourage her.I think having people at school is a help too,it can become a competition as to who gets their fixed braces first. But persist,it really is worth it.
My DD's orthodontist told us the key for DD was doing it at the right time when her bones were growing and therefore the jaw bones were growing and more likely to permanently stay in place. I don't know how long this time is, but I'd say would be far better to keep the braces in and they are permanently fused in the correct position. What your DD won't want is to find when she's no longer wearing the braces, her jaw moves part way back into position, as there's only so much they can do with permanent braces.