I was able to successfully foster the kits! For two days I force fed the kits by gently holding the doe above them, then on the 3rd day I put the kits in together with the doe's own kits and waited. It's been 2 days and the kits seem to be fine. The 4 orphaned kits are healthy and are always together with the other 2 kits snuggling each other. I'll post a clearer picture later.