Mine started with NXT16 at ~8-10yr old. When she started breaking that too often we went to hybrid poly-NXT. I think for your daughter current age and stage, soft copoly-multi in Babolat at low tension is fine. My 13 yr old is quite strong and developed physically but we will not risk her with a full bed poly yet. (maybe OK if I can afford cutting it out every 8 hr) We are trying this natural gut-copoly, not as harsh and lasted longer than copoly- multi at this stage. She hits regularly with D1 players for hitting lessons.