[mr_sir]

once you get the cutscene where she is sent to find you, she appears on your ship and you have a brief fight with her - you just have to keep getting on and off the ship til she turns up. the cutscene where she is sent to find you happens when you start getting reasonably far towards one alignment, i'm guessing in your case this would ds if you are fighting vrook.

if you equip the lightsaber with your crystal from the shyrack caves then it makes it a very useful weapon (also, throughout the game if you ask kreia about the cystal every now and then she will be able to make it even more powerful). i found when i did a ds sentinel against vrook that force powers were pretty much a waste of time. the best thing i found was to rely on melee to take him out, although he does do a lot of damage each hit sometimes.