Fixing the Cats

First of all, they weren't broken. They were prefectly normal, healthy cats who started going into heat quite regularly. I'm not fond of the word spayed either, reminds me of gardening tools.
Any way I took them in because spring approaches and I don't need litters of kittens. My biggest fear was that it would change their personalities. Misty, the grey one, is a spaz, loves to play and can jump half way up the wall. Freckles, the one with the orange face, is mellow and lovey. They always get along well, romping around the house and cleaning each other. We let them out in the backyard once and when we let them back in Misty kept hissing at Freckles. We figured it was something about her smell so I rubbed a banana peel on both of them. I didn't put a whole lot of thought into that, I just happenned to have it in my hand when Misty started hissing. It worked. I digress.
So I took them in and when I went back in the afternoon to pick them up Misty is the only one that could come home because Freckles was running a temperature. So I took Misty home and the next day went back for Freckles. Now Misty acts like she got a lobotomy. She hisses every time Freckles even looks her way. Freckles is her same old mellow self and just gives Misty the "whatever" look. I've tried petting Freckles then petting Misty but then she hisses at me. So I'm starting to think it's time for the banana treatment again. : )