What Causes Child To Reach Puberty At Early Age?

i have an 8 month old grandaughter, we seen some pubic hair growing , so we took her to the dr. he said shes going through puberty, i never heard of this, she is now just starting to see a hormone specialist, can you tell me more about this as i cant find any answers anywhere, what causes it, what will hapen to her, anything you can tell me, is there a name for this, i tried everything and i cant find anything on it. please help me if you can, im worried about her