Being short is probably the first reason they will turn someone away ... it's just too important.
As far as the face goes ... the stats show that being pretty is not going to make any difference. It's not about being "pretty" either ... it's about being photogenic and having the right look for what is currently desired by clients. Interesting is a good description for some very famous girls ... or unusual. A girl may be very pretty, beautiful, or gorgeous or any combination of those and have the height and body type, and still won't get signed. It's a very nebulous standard as to what the bookers are looking for.
But, a very tiny percentage of shorter girls with extraordinary faces occassionally get signed. So ... you will never know untill you spend a lot of days getting in front of agents to see if you have what they are looking for. But to overcome a lack of height, you must have that one face in a million ..... merely pretty or beautiful won't be enough.