Evil FSIL and Invites (Re-post from '05 Board)

So my wedding list is already insanely long...we both have huge families.

FH's parents included my FSIL's parents on their invite list and I do NOT want to invite them!!!

A little background:
-FSIL is a witch...she just married FH's brother last July...prior to the wedding I e-mailed and called and asked if I could help her with anything...
-I was not in her wedding (which I really did not want to be part of and was relieved) and she is not in mine
-FSIL has yet to congratulate me on the wedding, has never asked me about planning, etc.
-We see FSIL very rarely...

I really do not get along with her. She is just a nasty person and I have tried to reach out to her many times, and have finally given up.

She has done a lot of sketchy things (told ENTIRE family and sonme acquaintances they were having a baby before telling FH...I overheard her telling someone else!!! And then asks FH to be godfather...so strange!)

Also, I have only met FSIL's parents twice (and once was at her wedding!!)

I am sorry, but I get so crazy thinking about FSIL...it really bothers me that she will soon be my 'family' and she is so cold and nasty...I don't even want to invite her (although I know I have to)...

Do I have to invite her parents though? (we are already cutting some of our friends because the guest list is 280 right now and Riviera's max is 220!!!)