If Shelley were a MAN...
She would still be working regularly in film and television. So she tends to play prim-and-proper characters. Male actors get away with playing the same type of character all the time. (Even Oscar winner Jack Nicholson falls back on his typical persona time and time again.)
I don't think it's fair to hold Shelley to such high standards when Adam Sandler gets to make a career playing patented not-quite-grown-up-lovable-schlubs.
Respect Shelley!
The Nimble, Limber One.