@Emmycat, she does seem like a great candidate for Peace Corps (from one who has done it). I imagine that Peace Corps is suspended around the globe right now (hopefully a temporary situation). Lots of information and inspiration on the Peace Corps website if your D just wants to learn more at this point.
She would need to complete a degree first (only those with farm backgrounds or extensive life experience would be considered without a degree) and it’s a many-months long competitive vetting process to get in, so not something to do on a lark while deciding on a major, and it’s usually a 24 to 27 month commitment…not something you just sign up for (only saying that because so many people seem to have that perception).
It IS a great thing to do between an undergraduate degree and grad school, and enormous numbers of returned volunteers go back for a MPH or PhD in public health afterwards. Lots of volunteers study for GMATS or MCATS while overseas and take the tests at embassies or American schools abroad so they are ready to apply from the field or right after returning. Certain universities (Tulane, UNC, American and George Washington University come to mind) tend to be chock full of returned volunteers in public health, public policy, international development and social work programs. Having completed Peace Corps service is seen as a very strong part of an application to such programs…if anything, some students in these programs (especially in global health) may feel almost a minority if they have NOT done it or something comparable.
Good luck to your daughter…she sounds wonderful!