Again, my replies are mearly opinions, and shouldn't be thought of as anything else!
When you gained custody of your grandaughter, there should have been specifics mentioned then, as to visitation from either parent.
Personal Opinion: I would agree to let the mother have supervised visitation, or at least she have to travel to PA to visit, versus sending a 13 yr old, alone, on a cross-country flight.
Are you to pay for the flight to/from CA?? If that's the case, I understand, but I would suggest paying for the mother's ticket to PA instead, and she would need to provide board for herself, and her daughter for the visit. (motel, etc.)
I'm sure there are many more personal things involved here, that you wish to not explain, Let us know how things go!
