Are Sophia's parents vampires?

Question

As far as Sophia being a vampire, the anime never really addressed why she was a vampire, and her parents never commented on it. Is one or more of her parents also a vampire?

Answer 1

The light novels answer this. In short, no, neither of Sophia's parents are vampires. And given that the light novels actually specify that very few people have Appraise, and that high-level Appraise Stones are rare, it's entirely possible they're completely ignorant that Sophia is one. Though Sophia's parents are nobles, so it's possible they have access to an Appraisal Stone. It isn't clear whether they know Sophia is a vampire or not (I'll update if necessary, as I'm still reading volume 5).

The reason Sophia is a vampire is that Vampire was the unique skill assigned to her at birth. That each of the reincarnations were assigned a unique skill is also something the anime didn't really explain (at least as far as I can remember). Kumoko's was the skill Skanda, which increases her speed. Note that these unique skills are not necessarily one-of-a-kind, only for this reincarnation, as plenty of monsters are shown to have the Skanda skill. Back to Vampire, this skill gives Sophia the Vampire title as well, which comes with some really good skills like Undying Body (Which was evidently mistranslated as Immortality in the English version in volume 4, and corrected in volume 5 when they realized it wasn't the same thing. To be sure, there's a difference, because it only allows her to survive any attack at 1 HP, once per day, whereas Immortality lets one survive any kind of physical attack, with Abyss Magic or other attacks on the soul being the only way to fully kill someone with it.). Another really interesting thing, is that since Sophia was assigned Vampire from birth, she also gets the Progenitor title, which negates all negative effects of being a vampire.

Textual Evidence

Getting back to the main question; this all comes from volume 5 of the light novels.

From page 4 in Chapter 1: The Spider and the Vampire:

Does that mean her parents are vampires or what?

But according to Appraisal, the woman who's holding this baby is human.

The lady's name is Seras Keren.

Same last name as the baby bloodsucker.

If you put two and two together, that means this lady is definitely the kid's mother.

Her mother is human.

From page 6 in the same chapter:

So by the process of elimination, her reincarnation bonus skill is... Vampire?

Hmm? Hmmmm?

Which means that the reason this kid is a vampire is because that's what she got for being a reincarnation?

The description for the Vampire title did say that it gets added to your species when you get the skill.

From page 30 in Chapter 2: The Town:

Actually, aren't they nobles?

From what I saw earlier and all, I'm guessing the baby bloodsucker's father is in charge of the town.

His name is John Keren.

Race: Human. Human. I say it twice because it's important!

Good for you, Baby Drac! You're a vampire who was born to human parents via some freak mutation!

...

I don't know how vampires are treated in this world, but if an important noble suddenly has a vampire baby, that smells like it'll be trouble in the future.

Well, they'll have to deal with that themselves.