First, just take them home with you. Getting legal custody after you already have physical custody is much easier than taking the kids away from Child Protective Services (or whatever it is called in NY). And chances are good that nobody will ever even raise the issue. Second, get the mother's permission in writing. Even a short note would be better than nothing, and it would be nice to have that during the few days it will take you to accomplish step three. Third, have a family law attorney draw up a document for the mother to sign giving you power of attorney in all matters pertaining to the kids. That should be good enough for the schools. Fourth, if the attorney advises it, get yourself qualified with the county as a foster parent and then tell the county that you have the kids. If they assign the kids to you as foster parent, that make you the legal guardian. Don't try this without consulting a local family law attorney because that attorney might advice you to not alert the county that these children exist.
This answer must not be relied on as legal advice for the reasons posted here: http://mcgyverdisclaimer.blogspot.com . And I am not your attorney.
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