A high school senior made a grand entrance into her prom with a custom-made gown designed by her little sister. Mikayla Lewis, 18, says she had full confidence in her sister, 14-year-old Courtney, when it came to making her dress for the big night. That's because Courtney has some experience in fashion design and has made dresses for her sister in the past. The sisters worked on the dress together for two months leading up to prom night. InsideEdition.com's Mara Montalbano has more.