OOC:
I started to create a whole list of options based on what happens before Nydilind's turn, but it got very long very quickly. Basically, if possible, she will step back away from any hand-to-hand combat to take another shot with her bow at any drow still in the rear, not engaged in combat. If everyone charges and there's absolutely no engaged drow, then she'll go ahead and take the penalty for shooting into melee to be sure she doesn't hit any allies.

However, if they charge and she's engaged, she will drop the bow as a free action and draw her short sword and dagger and attack.