Cottage Living: Prep and Plans

I'm playing a family of 5, I have alot of plans of how their lives is going to be, their oldest I'm planning on her getting attacked by a vampire when she's a young adult and she's going to transform into a vampire, then she's going to move in with them, so I'm thinking beauty and beast sort of story, not exactly love at first sight lol, I'm wanting them to eventually get married and have a daughter, the middle child I'm wanting him to be into science, build robots and perhaps hopefully get an alien child ? perhaps I will let him get married and have 2 human children aswell, the youngest is still a toddler she was adopted into the family I might of cheated and gave her the spellcaster trait, I'm wanting her and her parents if they are still alive by that point to buy a cottage in the new world and farm animals etc, I'm wanting her to be a single mum basically to keep the spellcasters in the family, I've decided to only play one family and all my sims that I play will be related in some way