Thanks for the response!

Ok I will keep them apart for now although the little ones are keen explorers!

I have been a bit worried as I noticed that my exisiting cat has hissed for the first time ever. It happened when I had cleaned the kittens, and she sniffed my hand. Then when I tried to stroke her (or anyone else) that touch plus scent of the kittens makes her hiss. Quite scary as shes never done it before