My Strangetown was about to blow up when I did some fun SimPE finagling and have since kept it alive. By doing so, however, I somehow copied all of the pre-made EAxis sim families and some of the townies that I had married into my CAS sims. So, I wound up with an alien Chloe who was married to my self sim's kid who had their own child and another alien Chloe who I hadn't played. Both showed up in the family tree with the same parents, sibs, extended family, etc, but depending on the path I used to access the various families I would get either the played Chloe or the new Chloe to show up. Because of this snafu, the game allowed Chloe's son to marry his half-niece because the son was accessed via the played Chloe and the niece through the virgin Chloe. So, I fixed the dual character problem in SimPE, but now I have a family tree that doesn't branch.