Swollen leg in one cat and one cat leaves home

Question
I have a couple of questions for you.  We never had cats until a couple of years ago.  I brought home tiny brother and sister.  I had planned on putting them in my barn to be barn cats, however, they were so tiny that I kept them in the garage until they were bigger, then they never made it to the barn.  We moved 3 months ago (7 houses down the road), we took the cats, put everything in the garage the way it was at the old house, beds, litter box, food, etc.  and we did not let them come and go for a while until we felt like they knew their surroundings.  My female cat left and we found her at our old house after 14 days, she was skinny and scared.  Home again, then after about a month, it happens again, once again, we find her at the old house, she is not as skinny as she was the first time but VERY timid and scared.  Now, for the third time, she is gone again.  We are wondering, (a) does she have no sense of direction when she wonders to where the new house is, or (b) does she not like the new place or, (c) does not feel secure or just doesn't care one way or the other.  When she and her brother are home, we keep them in the garage unless we are out there and then we let them outside, when we go in, they go in.  Her brother wanders and always comes back.  At the old house, they use to always be in the garage, they would wander but usually be there in the morning and night but at this new house, the brother shows up at night and that is about all.  Last night he came home with his right front leg all swollen.  I messed with it and he does not act like it hurts, so I do not think it is broke but he is not putting much weight on it.  Any ideas?  

Answer
well she keeps going to the old home because that is what she considers her home, the boy's swollen leg could be a snake bite or a bee sting.

You probably just need to not let either of them out again, just make the big move to making them house cats and bring them in the house. they will be more comfortable in the house and you wont have to worry about them ever again.