We've been feeding a 'feral' calico off the back porch. Recently, she comes to sit by the back door, makes little sounds, seems to want to join the family. Trouble is, two other rescued female cats are already in our tiny house, and one of them is pretty territorial. We're sad we can't take her in, with winter on the horizon. We've been talking about setting up a shelter on the porch. No ideal solution is evident. Has anyone dealt with this before?