You need to bring them inside first, then if you can set them up in your bathroom or another room that they can be confined. If the bathroom or other room isn't an option, you can get a large dog crate to use.
It sounds like the Moms are close and will be fine raising their kittens together, if you see any problems, then separating them is needed.
First things first though, bring the Mom's inside or they are going to end up getting pregant again, and that isn't healthy for them. Once they have weaned their kittens, they can be spayed, to prevent any other pregnancies.
We enjoy seeing pictures. Good luck and please keep us updated.