I have thin , fine hair , that is down about six inches past my shoulders. i have to cut it very short because of all the heat damage i've done to it . I want semi permanent extensions that are the SAFEST route. i don't want to damage my hair while its growing out. but i have to cut it. what method is safest for growing out hair, besides clip ins?

please give any and all information possible. (prices etc.)
Oh and my mother is a proffesionall hairstylist and she would do them for me.

thanks!