"Our beautiful daughter is the light of our lives. Beyond thankful that she chose us to be her parents. I can't wait for her to be here next year," she wrote in the caption.
The video showed her lying in the ultrasound room smiling as the camera reveals her baby daughter on screen during the scan.
"This is so exciting. Look at our daughter, she's so beautiful," she said.
Her husband Chandler Powell, 24, said in the background of the video, "Wow, you can see her heartbeat there. Oh my goodness, she is beautiful and very active."
She previously shared a snap on Instagram updating fans with her progress, saying, "Twenty weeks pregnant and our baby girl is about the same size as a recently hatched emu chick."