Although the sim that first appears in CAS is always standard height, if you click on randomize, all the sim's characteristics change, including height. You do it using the randomize button located at the bottom of the panel on the upper left portion of the CAS screen. But not directly, since there is no slider for it.
Anyway, the answer is yes, you can adjust height. I realize this is a really old thread, but there are still a few of us playing Sims3 (and the answer might also apply to Sims4-I can't say for sure, since I don't play it).
