Dunno why this does not exists yet.. I have 2 computers. A notebook and a desktop. I cannot play on both with the same character.. And my girlfriend created a character on my computer that she wishes she could play at home, and some times on one of my computers... She is not very good at computers, so i cannot tell her to bring her char on a pen drive.. She will most likely give up The saves should be on the server.. Like MMORPGs.
Doesn't Steam support cloud syncing Starbound saves? I seem to remember hearing that it does. I dunno, I've never played around with it, but it might be worth looking into assuming you have the Steam version.
unfortunately Starbound does not have a Steam sync. I would suggest just showing her how to put a character on a flash drive.