@crinrict At first I just thought it was a one-off situation, didn't pay it much attention as thankfully there was always another sim in the household able to introduce the mother. But when it happened the second time I was like.. hold on just a moment.
Then I read around and figured it was a common bug that was supposed to be fixed with the patch.
This is when I created a new save, creates a couple, made the female be a 5 star celeb with the beloved trait. Then removed all the mods and everything, tried again with the baby. This time it worked fine.
I didn't remove the mods to try on my current save as I rely a lot on them during the gameplay and I'm always worried it's gonna mees up the game if I launch it without them, plus as I said, I realized It was a common problem after she already had the second baby. I am not planning on her having another one, otherwise I would try again to see what happens.
