Why does my female sim have mysterious children?

[Kickvic]

I just found out that my female sim has two kids with another woman  that and they are both young adults.[ I should of noticed before because I have MCC mod and I enabled child support and had to pay it. Which I thought was a mistake so brushed it off and payed it.] But looking at my family tree I just noticed that she has these kids. My famale sim cannot get anyone pregnant and she has female body parts, so I'm pretty confused on where these children came from. Also considering that woman had more kids with her husband. Thus getting pregnant from both men and women, which I don't think is an option in the game. So asking if anyone else had mysterious kids in the family tree like this and of anyone had the same strange situation. 

[Brian_Z]

How strange!  MCCC shouldn't be collecting child support for YA children either.
So your sim and this other woman are the actual parents?
Is your sim an npc that you now control?  Katrina Caliente has her daughters Nina and Dina, but no one else should show up as their parents, they start the game as young adults.
Oliana  Ngata has the custom gender option to impregnate others, but that option is either/or, there is no "both" option.  I see Leila get pregnant all the time, and MCCC does list Oliana as the partner.

[sdhoey]

This sounds like a question better asked over at MCCC page. They will be able to answer your question better

Shannon