Sims Freeplay

So, at first, I wanted to make a Sim game about some of my real life friends. I created my best friend and her boyfriend as playable Sims, but I also decided, before I realized the game had a virtual pet store, that I would create human versions of the 2 dogs (don't ask), and so I made the dogs fall in love, get married, etc. and made them both 'Good Friends' with my best friend's character, so they could move together (like a real family), but then, I decided that I wanted my best friend and her boyfriend to 'Get Married' and have a kid. So, I married them, bought a crib and spend my LP on the baby. The baby is now a Preteen Sim. With the one of the more recent game updates (maybe one or two updates ago), they added a feature on the character relationship thing, where if it's a family relation, it will say the relation (mother, father, son, daughter, etc.) under the character's name when they want them to interact with one another, and my game seems to think that that kid belongs to the 2 human-dogs, which they don't. They belong to the other couple in the house (my BFF and her BF). How do I make it that the child belongs to the other couple instead? Please help. Thanks.