Well we have just been thrashing this out, thank you for your comments, they have really helped.
OH felt we should give her the chance, I on the other hand played Devil's Advocate, partly because if we go down the keeping route, I don't want him to say he didn't know it would be so much trouble etc!
We went through the scenario of costs, c section, hand rearing, none of which unduly worried us, although I don't think he really understands almost 2 weeks of hand feeding!
Having then looked at some comments about the RSPCA hospital she would go to, along with your comments, we decided we couldn't do it and she deserves the chance. OH said that we should at least give her the weekend and is happy to throw £250 at her for a start off Nd then see what happens. He didn't mind hacking to pay for a c section if that was what was needed, but that I am going to be cheeky and ask the vet to charge at cost! They actually owe us a favour anyway!
So I left a mess. to say we will be taking her on and I will ring in the morning to confirm it.
So there we are, I am actually feeling a little bit queasy at what is ahead, there are no certainties that she,or the kittens will vet survive, but where there is life.....I spent last night nursing her and feeling those little kittens moving around, so while they are in her and she is getting the help she needs, there is hope.
I know that if we go over the initial £250 it won't matter, but it makes OH feel he is in control of costs ;)
Wish us luck are we mad? Hope I don't back out over night!