Your third photo shows young uncapped larvae, so she has been there within the last week.
I have found a few things that really help with finding the queen. One is to use as little smoke as possible. Queens really hate smoke, and may even dive onto the bottom board to avoid it. The other is to cover frames that you aren't inspecting with a pillowcase or tea towel. Don't use a fuzzy towel - bees get their legs caught in the fabric loops. I use 2 tea towels, and just leave a gap between them to lift the frame I am inspecting, then gradually move them over as I progress across the box. This keeps the light level down on the frames which you are not inspecting. The idea is to make life more comfortable for the queen and the nurse bees, neither of which are fond of sunlight. Marking the queen always helps too, but even a marked queen can be very elusive!