Michaela Onyenwere’s W.N.B.A. career began with a celebration that spread across social media timelines and mentions. When the Liberty drafted her No. 6 overall in April, a video stream of her dancing grandmother took center stage. Theresa Duru wore traditional Nigerian apparel, including a head tie, called a gele, that billowed toward the ceiling like a cumulus cloud as she busted moves and turned heads. Duru became a meme and a tagline: “We’re all Grandma.”