Yes she would. “Escaping” is only the first part. Staying hidden and staying safe is a whole different issue. You clearly don’t know what the fukk you’re talking about.
All it takes is for him to file court papers or charges on her for kidnapping and the next time the kids get registered for any school, the next time she does an I-9 or her taxes or files for any govt assistabce, the next time they do anything to start their new lives that gives a direct line to where they are.
But let me guess, they should have flown to Mexico with no money, got plastic surgery for her and her kids so that they were unrecognizable, got new social security numbers and lived their lives under assumed names.