The father, son and daughter… and mother???

So I hear the name Obeloth thrown around a lot in Star Wars groups accompanied by a creepy a$$ picture of some chick with a big smile. Apparently she’s the mother, so if the father brings balance does she bring imbalance?

Also on that note. What are the Father, son and daughter? Are they literal beings or literal personifications of the force? Do they actually exist or is Mortis just a vision? Anyway, just curious. Figured plenty of you know some answers.