The only problem would be if the board's too long for her. It would make it harder for her to turn and she won't effectively be able to control her speed. Somewhat of an issue for someone new to the sport. If the deck is the wrong size for her, she won't have any fun, and that would just create one more skiier. If this is the case she should rent and take a lesson.
If she is around your size then it's your duty as an older sister to turn her into a cool person.
Either way, the only damage I can see given her skill level is if she bumps boards with another person in the lift line, scratches the base on rocks, or smokes a tree. And any damage to the base can be fixed with a simple board tune-up
'12 Lib Tech T.rice / '12 Burton Cartels
'10 CustomX / '10 Co2 EST
Last edited by Dano; 12-28-2009 at 02:48 PM.