OMG - five!
I'd estimate them at a month or so - they're still very babyish but taking an interest in the food dish - however feral mothers tend to wean their kittens earlier. They can't leave her just yet of course and so with kitten season starting, the RSPCA etc are jibbing at having to trap a feral mother and provide room for 5 wild kittens.
Having been in this position myself, I would still keep plugging away at every charity I could. I lost my rag with the RSPCA once - they KNEW about the local feral colony but still tried to accuse me of trying to offload little illegitimates of my own. I shouted at them that I was doing their job...a week later they rang me back and offered the kittens I'd rescued (also from a shed but not my shed) a place in one of their shelters. So it does no harm to pester though by god it's exhausting. (By that time the CPL had taken the kittens.)
I did get some useful advice from one rescue organisation and that was to gently socialise the kittens. They stand a far better chance of finding homes then. If you have the time, although the mother cat may be annoyed, they're just the right age now and it can be a good idea to play with them gently - say with a long piece of dried grass or twig, getting them to chase closer and closer to you. Let them catch and 'kill' it, but all the time sitting quietly until they will actually climb all over you and get used to a human presence and scent - and then is the time to attempt quiet speaking and even stroking and eventually hand-feeding and picking up. I managed this with my kitties in 3 days - but they were in the bathroom and stuck with me lol. And they were 6/7 weeks and yelling at me for their grub, which was a great ice-breaker. Mama cat too may get used to your presence and be less wary. She might even start yelling for her grub too. Nursing mothers and weaning kittens have got hollow legs - as I expect your wallet has found out...
Are those grey ones tabbies or are they actually grey? Another plus for rehoming if they're an unusual colour - although again they need to be tame.
I take my hat off to you, you're doing so much and there is no way you should have to consider getting this lot neutered at your own expense - unless you happen to be a millionaire, which I'm sure you're not. There's a list of shelters on this forum - I'd contact the ones in your area too.
Other people on here may have some more ideas for help and rehoming - and a BIG congrats for caring so much, good on yer and all the very very best
