It's probably just from irritation. It would probably be best if you did not do anything like that for a few days to give her a "rest" in there.
if she started bleeding it could haven been her period or if she is a virgin it would cause her to bleed u touching her up there
It's really hard to say. Do you have really short fingernails or longer ones? It could have cut her. But it could also be the hymen. If so just using your fingers may not have completely severed it which would explain why she bled again the second time.