Lucy ran out of the room and came across Edmund, who was still hiding. Then Peter came in the room to see both of them out in the open. Susan then came into the room asking if she had won, implying Peter hadn't found her yet.
Of course, the book had the siblings looking around the house and opened this door to find this room with only a wardrobe in it. Lucy then lingered to try to open the wardrobe door, not sure if it would even open (thinking there may have been a lock on it). After finding the fur coats, she walked in, as she enjoyed the feel of the fur, something that only someone younger would do.
However, I do wonder about the number of coats she found in the wardrobe. They continued past where the back of the wardrobe should have been. Where did all of those other coats come from?
MrBob