Gwen Stefani celebrated her 51st birthday on Saturday, and was inundated with gifts from her friends and family.The No Doubt singer shared several videos of herself opening her presents at home in LA, surrounded by her loved ones, including boyfriend Blake Shelton.MORE: Gwen Stefani as a brunette needs to be seen to be believedIn one clip, The Voice judge told the country singer that she had received a beautiful bouquet of flowers.