Well, to be a short astronaut isn't something special. If i take a look at the heros of the early space flight era of NASA i'm rather surprised. Alan B. Sheppard, the first Mercury astronaut and first US astronaut ever was not airworthy anymore during the Gemini program in the mid 1960's. He was diagnosed with Ménière's disease (dizziness and nausea caused by the vestibular system). But after surgeries he became airworthy again and flew with Apollo 14 which was critized by some NASA people nevertheless.
Also, Donald K. Slayton was not airworthy for many years because of heart problems. So he became the Chief Astronaut and was responsible for crew selections "only". Because of his greatest dream, being a real astronaut, he stopped smoking, drinking and went in for daily sports as well as participated in a long medical program. He finally became airworthy and so a member of the ASTP crew in 1972 (his heart problems disappeared completely). He was the oldest rookie astronaut at that time (52)
And John H. Glenn, the first American astronaut who orbited the Earth, became the oldest human in space when he was 77. He was a crew member of the STS-95 mission in 1998. He also became the only astronaut until today who had a break of 36 years between two space flights
Everything is possible if you have a strong will. Being a short astronaut is one of the smallest problems