I am remodeling the master bathroom. We live in a tri-level house. The bath I am doing is on the bottom floor. The way the house is laid out is, Garage, master bed/bath and family room on bottom. The you go up a couple stairs and it is the living room, kitchen and dinning room. The you go the opposite way up about 10 stairs and you have 3 more bedrooms and a bath. This part of the house is over the family room and master bed/bath. The wall I want to take out is a wall in the masterbath. It has plumbing for the shower that runs down it coming from the ceiling. I don't think this is a LB wall. It is only 41 inches long and is in the middle of my bathroom. It was on of my shower walls.
If the wall runs parallel to the floor joist and the ceiling joist then it is probably not a load bearing wall. No way to tell from your description. On site inspection by an expert is probably the best.