I can't recall if I've said, but I was on Catalina Island, off CA, this winter for a few days, and they have a lot of material on the young Marilyn there. It was a very popular vacation spot with Hollywood stars---Natalie Wood drowned there---and lots of pictures of movie stars of that era cavorting. But before that, in WWII, it was a place where soldiers were stationed, including MM's first husband. Apparently (they say) this was where MM first realized the effect she had on men, she loved going to the beach full of soldiers...the impression is that the hubby was not to happy about this.
If you ever go there visit the little museum at the "casino" (which is not a casino--apparently in Italian that word means more like "gathering place")--it was a movie theater built when talkies first started, so it has a theater for silent films and one for talkies--lots of early premieres held there.