If your family member has no access to the said firearms it may be OK but I would contact a lawyer for some advice.
I maintain a residence in both states so my situation is different and far more clear cut than your's.
That's why I almost exclusively purchase firearms in NY. No fee for NICS, no OGAM, much better pricing. I would like to support a NJ dealer but NJ makes it financially imprudent to do so and the dealers I patronize in NY are my local dealers when I'm residing up here.