The Reliable Source appears to have the scoop: Michelle Fenty, wife of D.C. Mayor Adrian Fenty, has given birth to a healthy baby girl this morning. The gossip column is reporting that Aerin Alexandra Fenty was born at 6:08 a.m. at an undisclosed hospital in the city. Mother and baby are reportedly both doing just fine. According to BabyNameWizard.com, Aerin is an alternate spelling of the name Erin, which is derived from the Irish word…