I would not overthink the topic. Either her original topic (meeting new people) or the mission should be fine, depending on how it is written. The mission topic might be easier, since it is so specific. The original essay might be vague but if she can pull it off, great. These essays are rarely make or break, in my view.
There are free essay readers here on CC (go to the essay section). She can show an essay reader both if she wants.