youdontknowme From a rather pro-nudism perspective, I would argue that a bikini might even be more provocative than toplessness or full nudity is, because it sort of singles out the chest as an area that deserves special attention, which seems rather inappropriate to me with prepubescent girls. I would definitely favor a one-piece bathing suit for younger girls like that from a modesty perspective,
Sorry to editorialize but I find this all very interesting. One may say they are pro-nudism but also have very specific ideas about what exactly is appropriate and when and for whom.
I know my father has no problem with me being with boys while I am in a bikini but if they saw me in my underwear, which covers about the same, he would be very displeased.