Leighton Meester [1] has been laying low since giving birth to a baby girl [2] in September 2015. In the past year, we've seen her here and there: she made her first red carpet appearance since giving birth [3] in May and popped up for a rare appearance with Adam Brody [4] in August. Now that it's the holiday season, though, we can go back to a special moment from last year. Alongside singer/songwriter Dana Williams, the actress-turned-singer dropped a beautiful rendition of Elvis Presley's "Blue Christmas," sounding like an actual angel. It goes without saying that these ladies certainly have a way with covers. In 2014, the two blew us all away when they sang "Dreams" by Fleetwood Mac [5], but this one takes the cake.