"Dottie "Doc" McStuffins (voiced by Kiara Muhammad): The main character of the series. Doc is a six year old girl who likes to fix toys, dolls and stuffed animals. She also wants to be a doctor like her mother, one day. She is an African-American girl with short dark brown hair tied in pigtails with a fashionable headband in the middle of her head. She usually wears a lab coat underneath her shirt and pink-colored skirt with polka-dot stockings on her legs. Her name, Doc McStuffins, is also used for the series title."
Doc McStuffins is an American animated television series produced by Brown Bag Films. It premiered on March 23, 2012 on Disney Channel and Disney Junior. The series is about a six-year-old girl who can "fix" toys, with a little help from her stuffed animal friends.
The series debuted the same day as Disney Junior: The Channel, which is Disney-ABC's first preschool-oriented network in the United States.[1][2]
I have never heard of her either. Guess the grandsons are not into this show yet.