Thanks for the advise all. I'd rather not crate her as she was kept in a space pretty much 24/7 at her old home and she is a bit nervous of smaller spaces. I've moved the baby gate so it is on the kitchen and she sleeps and plays in there when we are not around - she seems happy enough. We also cover the baby gate in a blanket so she cant see them but they can all sniff and hear each other. Seems to be working so tonight I might leave the blanket off.
Both cats are becoming more curious of her, however she does tend to get excited and ruin the moment. For example she was asleep next to my partner and I on Sunday night and Frankenstein came to cuddle me like normal. He watched her but wasn't bothered. She woke up and spotted him, sniffed for a good few minutes but then yapped and he ran.
However, today she has hopefully learnt her lesson. She crept upstairs following my partner and encountered Trixie. Trixie has been the more frightened of the two cats so my partner kept a close eye on them but didn't interfere. Both Eddie and Trixie watched each other for a minute but then Eddie lost her cool and yapped. Trixie flew at her and smacked her nose! Eddie started crying and ran over to my partner who ignored her. She then followed my partner around looking sorry for herself...whilst Trixie stalked her. Trixie waited for the right moment then ran up and smacked Eddie's butt
We're still a long way off. Eddie does have to learn some manners, not just about being around cats. However in less than a week we are already seeing improvements. I'd like to think one day I'll have a cute picture of them all cuddled up but I will be happy with them all being in the same room without any drama!