The Fits introduces two startling talents: filmmaker Anna Rose Holmer, who has a preternaturally steady touch, and actress Royalty Hightower, who has a Sphinx-like gaze—until she smiles and her joy illuminates the screen. Hightower plays Toni, a Cincinnati 11-year-old who likes to box. At the local recreation center, she wears utilitarian workout wear and maintains a serious expression while taping her wrists and sparring with her older brother. But she’s intrigued by the loud, sparkly-dressed girls of the Lincoln Lionesses drill team…