Our son would kind of do the same thing. He would wake up because he had to go to the bathroom, and get up to "go." The crazy thing was, he didn't always make it to the bathroom. But he always relieved himself. So...we caught him peeing into trash cans in various rooms (including the bathroom!), found a puddle in the kitchen once, and once at the foot of our bed. It took awhile to figure out it was pee in the wrong places, but when we confronted him, he never remembered getting out of bed. He's a couple of years older now (10)...and always makes it to the bathroom toilet. We always listen and discovered his "typical" time to sleepwalk was a couple of hours or so after he went to bed. We nicknamed him "The midnight Pee-er" as it was always before midnight. Have you noticed your daughter's "noise" is before midnight? We could always sleep after that knowing he wouldn't likely get up and roam around.