Yes Ive had that scene, but I cant say my reaction to it was the same.
I was quite interested in speaking with the mother and learning more about the cairn and the ideal masters.
Maybe I didnt pay close enough attention.
Yes, the background is interesting, but the dialogue itself is so jarringly typical and painfully clichéd to me, and is inconsistent given the backstories and prior behavior of these characters. They're murderous necromantic vampires who worship molag bal, king of [censored], and have comitted unspeakable acts and rituals in his name. Maybe Serana was pressured into doing that, but she still seems way too ok with it and her personality is just inconsistent. It's just....I don't know. The backstories of these characters dont fit the family friendly, typical mother daughter conversations they're having. I've similar types of family issues involving vampires in Adventure Time for goodness sake (Marceline and Abadeer)
Edit: Make no mistake, something like this could be written well, but you have to make it either VERY believable or purposefully ironic (yet still somewhat believable) for it to work. It also needs to feel consistent with what we're given, and hopefully put a new spin on the original typicality to make it feel fresh. This does none of that in my opinion.