Lisa, I am so sorry that it isn't working out with Leila. Personally I would confine her to a room, if that is possible and start looking for another home for her, possibly without other cats. You have to do what is best for your own cats. There are just some cats that are better off alone and Leila sounds like one of them. You do so much for the cats that have crossed your path Lisa, I know you will do what is best for Leila.

Prayers and ((((((HUGS)))))) going out to you.