Jean Carnahan, the first Missouri woman to serve in the U.S. Senate and a former Missouri first lady, died Tuesday. She was 90. Carnahan died peacefully after a brief illness, a spokesperson for the family said in a statement. “Mom passed peacefully after a long and rich life,” her family said. “She was a fearless trailblazer. She was brilliant, creative, compassionate and dedicated to her family and her fellow Missourians.” Carnahan, a Democrat, was appointed to the Senate after her husband, Gov. Mel Carnahan, posthumously won election to the Senate after he was killed in a plane crash 22 day…