Katie Holmes has been completely unconvincing portraying grown-ups in her most recent roles. As an assistant D.A. in Batman Begins and as an investigative journalist in Thank You For Smoking (see below), Holmes looks like she's playing dress-up for Career Day. For the record, Holmes was born December 18, 1978, making her about 26 when she made Batman and 27 for Smoking.
What is it about Katie Holmes that makes her so hard to believe as a grown-up? Is it her childlike voice, baby face, or bad acting? Has she made a too-abrupt transition from playing teens to playing adults? Batman and Smoking are her first two roles as working professionals after a decade playing high school and college kids.
IMDb page, she has no new projects in the pipline. Perhaps the TomKat mating process will age her enough to play adults more convincingly in the future.