I can't find it still!
edit: Nevermind I got it :)
You're not going crazy... Rhose isn't on the list of names for a reason. If you do a search for Rhose Roottree on your in-game PC you will get a small hint about how you can find her. Often times, searching for things associated with people can reveal new information. For example brand names, or trying to find more details about what they do for a living.
If you need any additional hints, the discord server in the settings is a good place to ask, there are people who finished the game there that can help you.