Twilight (S3, The Crystal Empire), and her mother (S7, Once Upon a Zeppelin) are the only others who have used self-levitation before this point that aren't named Starlight, other than Pumpkin Cake, and I'm not sure that she counts for much on account of her being a baby.As for barriers, Shining Armor, Cadance, Flurry Heart (not surprising considering she's an alicorn and who her parents are), Twilight, Starlight, probably the Royal Sisters can do it… and Sweetie Belle.I think it's safe to say she likely has more magical potential than her sister, and I'd credit Twilight for helping her to learn to do this. I don't mind her being rather skilled with magic by any means.But yeah, there's zero evidence to indicate barriers or self-levitation are skills that are "basic magic", if so few have done it.