kitties under house

[H.P.]

Hello! Today, I found out that a stray momma kitty and her kittens are living under my house. The momma appears to be very young, I am guessing that the kittens are 6-8 weeks (I don't go to the back of the house very often). I think there are 5-6 kittens. The whole family is very skittish when it comes to me getting close. I have set out some food and water for them, to try and get them used to me. The kittens are eating dry food.I am not sure what else to do to get them out, or what I am going to do with them when I do catch them. Any advise? Thanks!
HP