I will tell you how I managed to get my simbot/human, Tavara Jolina. I downloaded Max Sims, Leto's sim. He has a ton of happiness points. I put him in a house and purchased 4 or 5 simbots and turned them loose. I then played Max for a while and kept watching in the friends panel what the simbots were up to. Sure enough, one of the simbots had a girlfriend, Jamie. So I decided to switch households and low and behold she was pregnant. It also showed that the simbot was her boyfriend, but was still not sure until after she had the baby, if it was a simbot. I believe there is another simbot that has a girlfriend too, but I have not played it for a while. It was pretty interesting.
But no, unfortunately, they cannot have babies when they are the active household. Weird.