Let's get real - Joe looks older than Norma!
Sure, Gloria Swanson was fifty in 1950, and William Holden was supposedly 32 (by his count). But she looked much younger than her years, and he looked fifty himself! Maybe he lied about his age as so many actors do, maybe he just looked older because he loved his booze.
I love this film and have seen it many times, but dayam. The dialogue about the characters' respective ages takes some willing suspension of disbelief.