how do you get triplets?

I'm making my sim watch the kid's network, read kid's books, i got her the fertile treatment/reward trait, and gave the lot the "On ley line" lot trait. I really hope doing all of these work, because i REALLY want triplets. My best friend has gotten them twice by getting the fertile trait, and she says that triplets are rascals, who darn near get taken away. I still want them, regardless...