Many very short women fly airlines. Some have to bring booster seats. There was a midget flying for mesa at one point (not sure the PC term, but he was apparently a really great guy), he presumably had to rig something up to reach the petals.

So really no limits at airlines. One airline I worked at had a lot of short older FA's... one of the planes they flew in the past had a low ceiling so they had to be under 5'6" or something like that to avoid OJI from bending over constantly.