I enjoyed this mostly for the stellar supporting performances by Jeffrey Dean Morgan as a much-sexier-than-real-life Joe DiMaggio, Stephen Bogaert as Arthur Miller, Tamara Hickey as Pat Kennedy Lawford and Susan Sarandon as Marilyn's mother, Gladys. They all made what is basically a run-of-the-mill Lifetime movie worthwhile.
Kelli Garner, in the main role as Marilyn Monroe, gives a breathy impression of Marilyn's famous speaking voice, but not much else. She never really conveys the conflict and pain of being Marilyn. It's like she's doing a celebrity impression instead of really becoming the character.
I know that it was made for basic cable and so they couldn't show much during the sex scenes, but it is particularly laughable when Marilyn and Joe DiMaggio are supposed to be having hot sex on a hotel bed but she leaves on her very visible granny panties and he doesn't even pull down his trousers, resulting in Morgan lying on top of Garner fully clothed while they grunt away. Surely the director could have found some way to make it look plausible that they might actually be having sex without offending the network censors.