I've been there. Maybe I'm twisted, but I make a game of it! lol Instead of having her counter it with two positives, this is what I would do:

For everything negative she said, I would counter with two positives myself! That drives people who are intent on being negative nuts! It really does catch people off guard in some situations. I especially like to do this when people are taking a negative attitude toward me personally- like if they point out a flaw of mine, I smile and talk about how it could be a strength. Or if they bash someone else, I pretty much ignore the rude comment and start saying nice things about that person. It depends on the situation what I'll say, but it's a lot of fun.

In my family, I really have had to learn to do that when I just can't take any more negativity. Because there is a lot of it. (Not that I don't contribute to it. Of course I do! That's the way I was raised)

Hope this helps!
Angela

-comfort the disturbed and disturb the comfortable-