Pennsylvania custody case was filed in the wrong county?

A friend is going through a custody case and is in need of some advice. The baby was born and lived in county A for over 6 months then they moved to another county B for 5 months. The mother moved to her parents house, county C right before 6 months was up in county B. They all live in Pennsylvania. The mother is trying to get the custody case in County C where the she took the baby and has been living there for a few days. The family has influence over the judicial system because they supposedly were able to get their son out from going to war after he was called up for duty recently. It's very important to get the case out of County C but they are having a tough time since it's supposedly up to the judge. The mother has been making false charges and lying flat out to help her case out. Her parents and her know how to play and take advantage of the system. Any advice would be great. They have a lawyer already.