I'm thinking jezebel might be the right term for Mary -- a shameless impudent scheming woman -- it works for her.
Or else a termagant -- a quarrelsome, scolding woman; a shrew.
I can think of a few other things to call her, but they're all along the lines of "ho" and not fit for public viewing.
Whoa...a tergamant. I like that even better than "Ho."
Thank you texasbluebell and cajungirl.
They say that brevity is the soul of wit.
A more biting commentary I could not craft. I wish you both and your families well.