Aww I like conflicts in my yuri but isn't the whole incest thing enough conflict? I'm not too fond of triangles, especially since from my past readings a third person that is very friendly to Ayako like this new girl usually gonna end up treat Asuka like trash behind her mother's back and because "something something incest is bad so it's better for mom to be with her and so I can get over mom" Asuka will not tell her mom about it (even though that would solve everything) until like 10 chapters later (because fuck your cute yuri we need forced drama). Well at least that's the worst case scenario I could imagine.
Considering this is a pretty drama heavy series this is really unlikely to happen, but I'm hoping this is just drama bait, you know, one of those new characters introduced in the end of a chapter and foreshadowed to cause a lot of trouble but it's just drama bait and she won't actually cause any trouble next chapter or she will cause trouble but in the end it was all a misunderstanding from Asuka's POV or something