Hi ,
I really think it won't matter too much which high school she goes to . After her Bac , she might want to do a BTS in tourism or 'airport careers' or something like that if you want her to do further studies . After that ( the Bac or BTS), she just need to do her flight attendant training with one of the specialised schools ( ESMA montpellier, for example only ) . In the mean time , you can always get her to do things like a first aid course , a BAFA , swimming practice ...maybe summer jobs in the service industry ...etc... and maybe an introduction to flying or a PPL at your local flying club ... Although , careful , she might change her mind and want to become a pilot