“Were they citizens at the time of her birth?”
Not sure that matters. Pretty sure you have to be the child of parent(s) born on US soil to be considered NBC. Harris’ kids will be NBC, but not her.
Pretty sure there are widely differing opinions of what NBC means. Last time I saw FReepers pontificating on the matter, the parents had to both be citizens. Period. Now you're adding requirements. That's fine; it's your personal opinion not legal advice.