Cannot set parents for pre-existing sims

I’m getting frustrated with this game. When trying to create my current young adult sim’s parents with the genetic tool in CAS it wouldn’t allow me to label them as “father “ or “mother” it only gave me the options of sibling or “partner” or “household member.” I’ve already tried “cas.fulleditmode” and it didn’t work. At first I thought I didn’t do the cheat correctly but I did. I’m on Xbox edition so I have no mods. I know I could delete my sim but it’s kinda annoying if I did that cause she already has a full family and other relationships. 

PS

it worked before with this save but I realized that the father was her step-father so I had delete both parents so idk if that affected anything.