So, after Dixie passed away in May (and thanks for all the lovely posts in response to my questions back then) we got her sister Tinkerbelle tested and she does not have FELV (phew!!)
We contacted the rescue centre we got them both from, and they offered us a new male kitten to keep Tinkerbelle company. He was older than her though (10 months, she is only 8 months now) and I kind of wanted a younger kitten for her. She's very timid and although she loves her cuddles, almost ANY new thing scares her until she has proven she can dominate it (furniture, food, toys, you name it!)
On Monday our vets posted on their facebook wall that they had a 9 week old female that had wandered in off the street. She wasn't chipped and by today, nobody had claimed her, so we have taken her on! She is very cute. Mostly black with white ears and chin, and VERY playful!
She is in her "safe" room at the moment, 6 hours after coming home, but the two have already "met"
Tinkerbelle has been unusually curious and both cats have been sniffing each other under the door and have been laying on either side of each other quite happily. So we introduced them. A few backwards steps, a few growls, a bit of a tail wag, and some posturing and they seemed happy in each other's space. Not best friends, but happy in the same room.
We have separated them again as there were a few slaps from Tinkerbelle, and we want her to be sure that her whole house hasn't been stolen!
I hope that a few more encounters and they'll be happy to play together!