Melissa Rivers took over Joan Rivers' Twitter account on Thanksgiving, sharing a gorgeous throwback photo of her and her late mother. "I finally figured out my mom's password," she tweeted from Joan's account. "HAPPY THANKSGIVING! Xo Melissa." I finally figured out my mom's password HAPPY THANKSGIVING! Xo Melissa. pic.twitter.com/giTnL2qwnO— Joan Rivers (@Joan_Rivers) November 27, 2014 Page Six reports that Melissa will host dinner tonight at Joan's Upper East Side condo.