What if the girl is 14 and the boy is 16 and they had consensual sex and now the police know. Is the girle also facing issues with juvenile court?

It is not likely the 14 year old will be treated as a perpetrator, but rather a victim. The 14 year old may undergo a medical and mental evaluation and possibly some court ordered counseling; aside from that, the 14 year old will likely be seen as the victim in the family court system.

In order for a crime to exist, there generally must be a victim. Since the 16 year old is old enough to legally consent to sexual intercourse and the 14 year old is not, the 16 year old, in most states, would be seen as the perpetrator of the crime.