Legal Question in Family Law in California

You are going to need an MA attorney. The MA courts retain jurisdiction unless and until both parents have moved out of state AND someone petitions the court to relinquish jurisdiction in favor of the new state of residence of the child. There is no requirement that such a motion be filed, and if no such motion is filed, the courts of the child's new home state will simply enforce any orders of the original state's courts. The logical process then is to simply file your motion in MA, have it heard in MA and if you win and the mother does not comply, you file with the PA court for enforcement of the MA orders. Once you have the child in CA, it is up to you whether you want to bother then to ask the MA court to relinquish jurisdiction to CA.