Snodderly is right. Do what you feel is right. After all, you know where it comes from.
I should have explained myself a bit better. If you do wish her a Happy Mother's Day, she may just turn it on you as if you're rubbing it in her face. That is evidenced by the comment she made to your son about the laundry, not to mention your other son refusing to see her.
If you don't do it, she may use it as justification as to why she left.
Last year on Father's Day, I texted my H. I said Happy Father's Day and thanked him for our beautiful children. There was no response and I didn't expect one. It just felt right for me to do that.
