They are the children of a wealthy Armenian-American man in SoCal (I’m not sure if he was an investor or a plastic surgeon, both of which groups are fabulously wealthy) whose wife decided when the girls were little that she wanted them to be “celebrities.” I don’t know exactly how she achieved this, but evidently the parents kept sending videos, photos and articles about them to the press and getting them into celebrity events...and presto, instant celebrity. SFAIK, girls have not done a darn thing, not even appearing in lousy movies.
You’re asking the exact same question I asked when their photos started appearing on the covers of supermarket magazines, which is normally how I keep up with “celebs,” since I don’t watch much TV and wouldn’t know a celebrity if one bit me.
Their father, who is now deceased, helped defend OJ Simpson during his circus trial. The mother married Bruce Jennar(Olympic athlete).