Umm... I wasn't finished and accidentally hit send.
I just wanted to say that there are a few ppl out there willing to take in older cats. We have three and 2 were adopted (from shelters) at an older age. I felt sorry for them because I was afraid that nobody else would want them. Hopefully you'll find someone in your area who wants her older cat.
Perhaps a little more time might help. One of our cats still dislikes Bella. She swats/hisses (she's declawed) at her all the time. Bella has learned to leave her alone and the cat the same. The other two, although nervous at first, now get get along great w/her. When they don't want to be bothered, they find somewhere to be that she can't get to.
Good luck!