I noticed that the cover clearly shows Louise's height as 4' and although less clear, Tina's at around 4' 9".
See? Louise lines up exactly with the four foot line and Tina is just short of the five foot line.
I'm not sure that, being a script cover, it could be considered an accurate source for this type of information. (As in character's heights)
Also it shows Rudy being 4' tall as well, and Tammy seems to be about 4'7".