I don't think she was sleepwalking because she reacted with shock and surprise when she went to the bathroom then obivously another woman was in there and she did not want to see that, just the fact that there was another woman in the bathroom was enough to make her leave. I think someone who is sleepwalking is not going to be shocked or be surprised and will walk right into the bathroom then she would of have had to shake her up really hard until she is shook wide awake. In any case, it might be better to have a hidden video camera set up during the night to record her movements and have family and friends stay up outside during the night time without her knowledge and they can watch the door from a distance and if she really is a sleepwalker then she will need to see the doctor about her sleepwalking situation which is really not safe for her. What if she walked out of the door and then gets hit by a car or what if she walked into the street and there were a group of drunk guys in the middle of the night and they see her then they take advantage of her. That is really not safe for her so you might want to set up a 3 night observance without her knowing it then see what the situation really is so you can help her much better.
But, shocked/surprised ? I don't think so.... 
