Wow. Just wow. Man, does your SIL know the person I was referring to in my "rant:deadbeats" thread?
I think if even half of your aborted email is true it should be said. Though I think I can understand why your wife didn't want you to send it. If your MIL has been drained and the tank is empty, she'll be out of your life soon enough, so why cause further stress?
Either way, that absolutely sucks. I can't believe anyone would ever be so callous and uncaring.