OK - funny - phone just rang. MIL.
I just double checked, and though the original message said the graduation is from 11-1 on Monday, it's apparently not until 2:00. There's a reception immediately afterward, but then the dinner ressie is at 6:00 at Legal Seafood. Perfectly acceptable time for the boys, and we love the (casual!!!) restaurant.
But, since the grad is in the afternoon, all we have to do is the dinner, and that makes me happy in regards to kind of forcing MIL to spend time with the graduate instead of us.
So, I'm glad that nothing had to be changed, but I still have a kind of bad taste in my mouth over her attitude...