Is this child abandonment?

ok, i live in NY.. this girl is 25 yrs old. she has a 5 year old son and a 2 year old daughter, by different guys. the girls father has nothing to do with her and the boys father takes care of both kids. she hasnt seen the kids in almost 3 months. he lives in the city and she just moved and refuses to tell him where. she changed her cell number too so no one can contact her. i was wondering about the abandonment laws in NY? does this constitute as abandonment? i know the kids are taken care of, but for her not to tell him where she is??