Question about having children?

[rose stirrup]

I'm not sure if it's possible to have children even though the rooms are closed, and it says that I have to extend the house. But I can't extend the house any more. What do I have to do to know that I can have children and how do I open the rooms? Can someone tell me what I have to do? My partner is already at 15 hearts and I have the house at 4!

[strong bronze]

The room(s) will automatically open day your child needs it!

(The doors, same for spouse room door, exist now to indicate room available BUT bc rooms aren’t accessible by player for decorating, devs had switched it from empty open rooms when unused to being a closed door instead)