weeze, if the mama and kittens are in a safe place, you might want to set up a covered box or something of the sort with soft towels, and place the kittens in it at the place where you have found them. If they are exposed to danger, then I would attempt to trap mama by placing the kittens in the large cage-trap and then remove them to someplace indoors where she and her brood will be safe. Keep her and her kittens confined in a safe room. Be sure there is plenty of good food for her to eat. You might purchase a few cans of meaty cat food, such as tuna, when you move them. Don't forget their fresh water.