Nikki Bella and Brie Bella posed nude in black-and-white maternity photos in their third trimesters.“I have embraced the changes of the human body, even though that can be tough at times,” Nikki, 36, captioned a Monday, July 6, Instagram slideshow of herself and her twin sister. “I have embraced the feeling of being uncomfortable knowing I am growing a life that will be one of my own.