If they made a character find a new family member, who should it be?

Say that, in a future movie or TV Series Episode, someone finds a new family member or a new family member is introduced. Who should it be that gets one? Or should it be more than one that gets one? Also, in addition to new family members, should they ever show what happened to old family members (Petrie's father, Cera's mother, Spike's parents, etc)?

Littlefoot