^unless the 2nd WN had some reveal, then no. They're just two orphans that they adopted (Mei and Alea).
Also I don't recall their appearance ever being described in the novel so this might just be the illustrator doing their own thing but who knows
^^I don't get the impression Ragyo would be interested in anybody other than her own flesh and blood. She probably only slept with a man in order to create daughters to molest.