Babies in Tomodachi Life are completely random acts of accidents. As long as a couple is married and are in good terms with each other, you’ll eventually have a baby… eventually.
As an update, it took about a week for the baby to grow up, when she was old enough there's a choice of either having them live in the apartment building, or sending them off 'on an adventure.
*Make sure you have babies enabled in the town hall! Its in the Town Hall, Options, Baby Settings, Toggle On
You can check the relationship status by pressing the L or R button in your Mii’s apartment.
If they’re married and want to have kids, the apartment window will indicate a romance icon.
Tomodachi Life Baby Names
Once the baby is born, you can actually choose the gender for the baby, or let chance decide. Then you can have the parents suggest a name or offer your own name. You can also change the way the baby looks! At such a young age. But because the baby is so young, you can’t really tell how s/he will look until s/he’s much older. You will be given another option to change the name, the way s/he looks and personality features.
So a few days after getting married in Tomodachi Life, my Mii told me that she was thinking about having a baby. I was completely alright with that.Within the week, she gave birth to a beautiful baby girl!
She asked me about how she looks and I thought it was too funny to say “Hmm?” to whether or not her daughter was cute.