Why do neglected kids disappear from existence? LOL

I'm playing semi-rotationally (sometimes Long/Short Aging On while switching between the families and sometimes Off) an expanded legacy family save that I created with my friend and it is so sad that when my friend made the matriarch had her first twin boys, the other one was unintentionally neglected (by my friend, she had a LOT of work to do :D ) and it got taken away by the social worker service. So sad that Markes won't meet his twin brother, Jotes, ever again…