She's just gray.
Dapple gray is just a stage of the graying process. Nothing all that special about it other than it happens to be pretty.
Fleabitten gray is referred to as, like the picture in the above post shows, a horse who has little ticks of their base color still showing, called fleabites.
Congrats on keeping her that clean though. Most grays I know pride themselves in being as dirty as possible. :P