Sarah, I agree with Laura and Nema. Don't push any more. It's human nature the harder someone pushes to change another person's opinion, the more stubborn the other person becomes. That person values their opinion, even if it's wrong, and telling them their opinion is invalid to most people will at least be aggravating if not infuriating. As someone else said, the ball is in her court. Let her make the next move and if it doesn't come, at least you tried.
As far as the Christmas presents go, and others may disagree with me, I would send them with no name as to who they are from. That way you aren't forcing her into an action such as withholding the presents from your nieces but she's not forcing you into an action of using an invalid name.
Bev
