Very beautiful! Your interpretation of the humanized "Mane 6" is really something to behold! Worthy of a good, solid critique! Each outfit has a brilliant retro feeling like something girls could put together at American Apparel; they match the girls' personalities so well.
Rarity is definitely playing up the 90s version of rockabilly style with her own sophisticated twist of course! Here I'm reminded of my head canon idea that she could be a special, rare blend of racial backgrounds; the 1 that stays with me the most is that she could be 1/2 French-Canadian & 1/2 Chinese. Makes sense to me given the culinary & artistic traits present in both cultures.
Fluttershy is demure & pretty as ever! The simple dress & sash with big boots & pastel tights are things that she really could wear. Your interpretation of her reenforces my idea that she could be 1/2 white & 1/2 Indian: a beautiful combination.
Twilight Sparkle is a true 90s girl in her outfit; reminds me of girls I went to school with. Yes, her snap-bracelet & bold, bright watch are the icing on the cake! To me, she looks Filipina, which would be really cool! Well, I'd like to think so.
Rainbow Dash always felt like she was Latina to me; I can definitely see it here! You don't disappoint with the tie-dye shirt, black yoga pants & big Air Jordan-style shoes. Nice job keeping her athletic personality as well.
Pinkie Pie is totally 80s! I always pictured her as Scots/Irish with that crazy hair of hers. That's the kind of ultra-bright, neon ensemble that suits her perfectly! The pedal pushers & ballet slippers allow her to run & jump to her hearts content; the best touches are the arm gauntlets & loose belts. Like I said: Totally 80s!
Applejack is the same jolly country girl I would expect to see around the Oklahoma/Texas panhandles. The boots, faded jeans & work gloves suit her perfectly, glad you remembered her trademark hat. The sleeveless plaid shirt with green cami are good for a hot day: she's definitely got the arms I would expect to see on her: muscular & lean.
Excellent work, my dear! An instant favorite for me! I am impressed.