Capaldi was born in La Jolla, California, and resides in Carlsbad, California with her parents. She began acting with small roles in the Disney Channel Original Series ANT Farm and in the CBS comedy How I Met Your Mother, as a 7-year-old Lily, who is played as an adult by Alyson Hannigan. In addition, Capaldi was featured in the pilot for The Goodwin Games. Capaldi also stars in Corbin Bernsen's independent film 3 Day Test and in Dog with a Blog on Disney Channel, her series regular debut. She started her voicing career as the voice of the Little Red-Haired Girl in the 2015 film The Peanuts Movie.