Too much drama - holiday time issues?

I do not talk to my SIL. makes for uncomfortable holiday situations obviously. she's a mess and a half - i dont mind not talking to her. however, my husband feels like i should just bite my tongue and make nice when we have to see her. I do, but my first choice is to not be around her. He on the other hand, doesnt want to avoid her - he just ignores/appeases her and he's done. If i did that, we'd have to see her much more often, and I dont want her around my kids anyway. last time i was 'nice' i got a phone call the next day asking me all sorts of crazy about things that happened years ago. problem is my husbands immediate family just 'puts up with her' for various reasons - no choice, grandkids, etc. The extended family agrees with me, but I dont know how verbal they are about it - and Im not one to throw them under the bus about it. Am I wrong to want to just avoid her or should I be putting up with the drama like everyone else? How do I get through to my husband??