Update -
My son asked to go to the circus Sunday, so I asked her to join us for Mother's Day and she agreed - with minimal conversation and one mildly snippy note about all the "printing" I've been doing from the net lately (left some info on Marital Separation Agreements out for her to snoop)...Any thoughts?

My son and I got her a fun gift for Mom's Day - nothing romantic - we'll wrap it Saturday and maybe buy her some flowers/cards, again "from him" or non-romantic from me. I hope that's the right way to go.