In S03E08 of Dark, it is revealed that:
Regina is the daughter of Claudia and Bernt Doppler (from the photo above fireplace)
Now, Helge Doppler used to be the father of Peter Doppler who is turn the son of Bernt Doppler and Greta Doppler. So, that makes:
Regina to be Peter's aunt.
Am I right? Is Peter related to Regina?
Now, there can be a slight discrepancy:
Helge Doppler was the son of Bernd and Greta Doppler according to fandom. But in the official Dark website, there is a mention of a third person (Anatol Veilev) with whom Greta bore a child which turns out to be Helge. If Anatol exists in the origin world and the same situation happens there, Regina would become a half-aunt of Peter (not sharing blood).
Am I right? Is Peter related to Regina in the origin world, too?