Reba celebrated her 55th birthday on Sunday, and her pal Melissa Peterman was on top of it. Reba and Melissa, who also co-starred in Reba's self-titled sitcom as Barbara Jean, are sharing the stage for a portion of Reba's set during her current tour with George Strait, and Melissa led their Saturday night audience in Tacoma, Washington in singing "Happy Birthday" to Reba.