Eating strawberries and listening to pop music supposedly is supposed to make you have a girl , I've never heard that it has anything to do with twins though. Hope this helps :)
Blah. My sims keep having twins,
I deleted one of the twins because I’m not trying to go down that road again, I don’t even have the ley line trait on their home, and I feel like I’m doing something that encourages them to on accident? I think watching children’s TV encourages it, so google is telling me, now.