How can 14 year girl grow taller before puberty?

Probably done. Most 14 year old girls are starting to fuse their growth plates and are at the end of puberty. If she hasn't had breast development yet, then she needs to see a pediatric endocrinologist.
Confusing question. Puberty is a transition period between into the young adult body that can be as short as 3 or as long as 7 years. It begins in girls with nipple enlargement , progresses through a growth phase and the onset of menses, and ends a year or so later after the growth centers of the long bones have closed. Good basic nutrition, health & proper rest help any kid reach their best height.