Huge mistake. I gave him advice. Wow.

[Lil]

Can she be arrested or made to return my grandson?

Short answer, yes. Parental kidnapping is a felony. Of course, to be honest, you have to find them first and then you have to extradite, etc. So it's not simple, but she can be prosecuted and the child would be taken into custody and returned to his father, who would pretty definitely then get full custody.