Oh fucking hell you're one of those people who thinks pointing at something magically solves problems? Bringing attention to something doesn't change it. That's not how anything works. You have to actually do things, and sure she has (most celebrities have, it's part of the job), but I can't speak for whether or not she genuinely cares, and nor can you or anyone else for that matter. We can't read minds. We don't know her motives. What I can say, is that to the best of my knowledge her actions associated with the UN haven't been especially meaningful nor was her talk (at least the one I saw) especially insightful. She's probably done other things, I would fucking hope so, but that example you gave isn't very convincing.