I had a weird issue when playing with a family today. I was playing a pre-made family (a male sim and his girlfriend) and the male sim has a brother that lives on another lot. He has his brother in the relationship panel and it has the family symbol under his brothers name. Now, he has never met his sister-in-law, nor his nephew, both of whom happened to walk by the house today (she was pushing him in a stroller). I had him introduce himself to his sister-in-law, but there was no family symbol under her name in the relationship panel like there usually is.
I even tried the romantic social "ask if single" on her. The game brought up the pop up that she was married, and the brother's name appeared as her partner, but my Sim still doesn't seem to acknowledge her as his sister-in-law. I didn't try socializing with his nephew because no options were available so I don't know if he'd recognize his nephew as family.
What's going on? I know that in-laws were always acknowledged in the relationship panel every other time I have played families in the past.