I don't think you have much to worry about. Make sure you document on a calandar the time you have him while you are separated so it shows a pattern.Now, yes, worse case scenario she could get crappy advice that she doesn't have to send the child until a court tells her she has to - but that only happens when they think you are a threat, and will do the same thing - I don't see that as a probability in this - it sounds as if although you are splitting, the two of you both realize how important it is for your son to be a big part of both of your lives...
Since NJ doesn't recognize legal separation, the sooner you two file and get a temp agreement in place, the better.
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