I wasn't questioning; heck, the way she was popping them out, I wouldn't be surprised.
I am thinking that these two children, not having been around the rest of the clan forever, were able to see through the manipulation.
Here's a link I discovered some months ago that lists the members of both families (Rocha and Peterson).
Jackie had two or three illegitimate children that she adopted out.
http://www.crimenews2000.com/lacipeterson/who/who1.htm