Oh, she's with her. Galadriel had no desire to face down a Balrog. You might not think it to look at her, but she's a fair sprinter.

The problem is, of course, that, being creatures of shadow and flame, Balrogs move much swifter than elves or humans can hope to. The creature is gaining; if they have any hope of outrunning the thing, they are going to have to pull some tricky maneuvers.