There are a number of pages that are relevant, for example this (Lehigh county), this written by MidPenn Legal Services, this (PAlawhelp) and this (Erie County). There is no statute regarding emancipation, which means that the courts deal with the issue on an ad hoc basis. The process is basically that you file a petition with the Court of Common Pleas, ...
If a lawyer . . . provides legal advice to family member, advocating
they take a child out of state, without filing an order of protection,
an emergency order, petition states the defendant's belief that the
child was at risk if left with the other parent, then are they
potentiality for engaging in custodial interference?
No. The lawyer is not ...
It has to be in writing
To prove it exists you can point to it and say “that’s it”.
Further, to be valid it must be stated on the record in court or before a Judge Pro Tem, before a court reporter, or any other mediator or settlement conference officer appointed by the court to conduct a settlement conference. They’ll have a copy of it.