Set my sims relationship

[HLP98]

I am currently playing a family of 3 father son and I was just having a random living with them to become the sons baby mamma but iv accidentally set her as his sister now I can’t change it back I have tried cas fulledit mode and when I’m trying to change it to household member it doesn’t  do anything just stays as sister non of them change when I try is there any other way to change this relationship 

[2cool4u_1]

You can do it with MCCC. Under Relationships, Delete relationship between her and the others.