ROLLING IN THE VOGUE COVERS?: Adele has racked up a string of magazine covers this year, including Cosmopolitan, British Vogue and The Gentlewoman — and now she may land the biggest cover prize around with American Vogue. Designers have been asked by the title to make special cover outfits for the full-figured chart-topper for the all-important March issue, sources said. Adele is not a sample size, wearing a U.K. size 16, or U.S. 14. She was previously profiled in the April 2009 issue of Vogue. Her second album, “21,” is this year’s biggest-selling record, according to Billboard, and she was nominated last month for six Grammy awards. A spokeswoman for Vogue declined to comment.