C and D had actual kids, so they're out. I'm gonna go with A and B. I'm very certain with Eirin since I don't think Omoikane even had kids, and the Watatsuki sisters seem to be just her students. As for Yukari... Ran and Chen are just her pets/computers, so they don't count – unless we're willing to entertain the idea that she's actually Marisa's mother 😏