Yamini part of mahishmati bloodline???

I was thinking as Yamini Is only step sister of sangram Singh n based at her character sketch, I think it is possible that her mother might have been from mahismati kingdom who had come to take Mani by hook or crook. So might have married the then raja n might have died in the process or changed the mind. Else how do you account for pure black Yamini Singh n pure white sangram Singh as siblings 😆