My cat doesnt like other cats

Question
I have a 3 year old cat (Emily) that we got from a rescue center. They had her in a room all by herself because they said she was very unfriendly towards the other cats. They also said that she came from a home where there were 7 other cats?!

Anyway, we recently had a stray pregnant cat show up at our doorstep every day and she went into labor 2 weeks later in our backyard. I prepared a room in the house for 'Cal' to keep her kittens and it is separated from the rest of the house. But, it is now a couple weeks later and Cal wants to get out of the room for short periods now and then, and we let her.

Emily is very nasty, hissing at her when she comes out into the rest of the house and is in a generally bad mood most of the time. If I have just handled Cal and then pet Emily, she hisses at me because she smells Cal on my hands.

I intend to find homes for Cal and her kittens, but would like to bring another cat into our home eventually. Is there anything I can do to help Emily to overcome her dislike of other cats. (She is also very nasty to several strays that we feed regularly).

Thanks very much in advance for your help.  

Answer
Was she abused? Your vet may be able to help. They have pet psychologists who can also help. I am not sure if the baby powder trick would be a good idea for her. The baby powder trick states to put on baby powder on both of them for a few weeks. The idea is to have them think they are family by the smell. Not all baby powder is cat safe. Also some vets do not recommend this. You should ask your vet if it's a good idea to try this. Watch the cats when doing this.


Good luck and ask follow ups