Why has no one challenged her that? Her parents were not citizens at the time of her birth.
Nobody challenged Ted Cruz and unlike Harris, he wasn't even born in America. And by "challenge" I mean a serious legal challenge, not just bleating on Internet forums.
This being said, I have little doubt that had Cruz secured the nomination, we would have heard more of it and had Cruz actually beat Hillary, the ongoing debate over his eligibility would have made the Mueller investigation look like night court.
I can only speculate that nobody really thinks the DNC would dare or risk running another ineligible candidate after the obammy disaster — especially since even sorozNazi must realize he can find 1000s of ELIGIBLE puppets to nominate that will do his bidding without the onus/ problem/disadvantage
Neither were Bobby Jindahl, Little Marco, Mia Love, Nikki Haley nor Cubanadian Beautiful Ted.