Graduated Early/Dead Teens

Sul Sul, 

I play multiple families of the same tree. I tend to have all the teens graduate early, work on their skills, go to university etc.  I have noticed that when I send my teens from the other households, they will come back asking if they can invite a classmate over. These classmates tend to be their cousins that have already graduated or in the most recent case, dead. 

Is it just me or can this be fixed?