Sim not Appearing in Family Portrait

[xFezIsAFreakx]

Fljotavik, the second generation heir in my Immortal Dynasty, has aged up to a teen and has now disappeared from the family portrait at the opening menu at the start of the game. He is one of eight sims and a cat, so possibly he just couldn't fit? It's not a game breaker or anything, I've just never had this happen and I'm paranoid it may be a sign pointing to a future missing sim bug or something. So yea, I'd just like to know if this is normal?

This is what I'm talking about:

[Ricalynn]

There are only a certain number of slots for people to stand in that picture.  I've had the non paired Sim disappear before but they were still there.  It happened to Rosemary in my dynasty file but she was there until her death at 110. 

[xFezIsAFreakx]

There are only a certain number of slots for people to stand in that picture.  I've had the non paired Sim disappear before but they were still there.  It happened to Rosemary in my dynasty file but she was there until her death at 110. 

Oh, that's good news! I'm playing the file right now and Fljotavik became invisible and I had to reset him and I had a heart attack thinking it was to do with this. Thanks, Rica!