meaning of "walk the edges"

I'm reading The Berry Pickers by Amanda Peters. In Chapter 12, the narrator described how she cleaned the house and packed up everything after sending her mother to a retirement home. She cleared out all the closets, and then :

"I wandered aimlessly from room to room. I walked the edges and looked into empty closets. I dragged my finger along the windowpanes and brought up dust, a sure sign that my mother hadn’t lived in her own home in a while."

I don't understand what "walk the edges" mean here. I wondered if it was an idiom but I couldn't find a definition in an idiom dictionary. Does it simply mean that she walked by the edges of things in the room? If not, what does it mean?

I would say that it means she walked around the edge of each room (alongside the walls). If you think about the rooms in an inhabited house, most of the furniture is pressed up against the walls so you don't actually see the "edges" of the rooms. In an empty house, you can suddenly see the entirety of the rooms - the whole walls, the skirting boards, everything from floor to ceiling.