FYI the spot I’ve personally seen her at most often is not listed on the app at all. When you first enter Disneyland there is often a princess or two with a very short line under the shade of the trees to the right and left of the Mickey floral display. They change out frequently, don’t stay long, & won’t show up on the app. I’ve always just counted it as extra pixiedust & never bothered asking but I wonder for your situation if you asked someone at city hall as you enter if they would be able to give you a schedule of these surprise/bonus character meets. I saw Mulan there 3 out of 4 days of my last trip and twice on my trip before that one.