Growing up in zero G? I'm afraid the problems would be substantial. Not being able to walk, improperly formed skeleton and organs, extremely weak immune system, and I'm guessing much more...

What's the zero-G impact on the immune system? (genuine question)

In short, it wrecks it:

http://www.nasa.gov/mission_pages/station/research/news/T_Ce...

http://www.nasa.gov/content/study-reveals-immune-system-is-d...

http://www.space.com/4302-stresses-immune-organs.html

Rotate the ship fast enough to mimic 1G gravity... Solved!