My mother, and my grandfather, are both humans. And... we suspect there's diluting, but assuming that what I have now is the height of things, would be foolish. At least grandmother thinks so.

Stuff like this... is all really new. A lot of vampiric clans in the 12 Dimensions are all undead, so they don't reproduce like humans would. Grandmother's clan, and very few others, aren't undead, so stuff like this... isn't very common.