Heidi is an orphan who lived with her aunt until she was 5 years old. When her aunt finds a good job which would not leave her the time to take care of a child, she decides to let Heidi live with her grandfather. Her real name (baptism name) is Adelheid. Heidi is a German surname.

Heidi: Girl of the Alps
After becoming an orphan, Heidi is forced to live with her grandfather Öhi, who lives in the Alps. She learns he's a very bitter man who only accepted by force to take her in. But Heidi's kindness may be able to open his heart. Together with the shepherd Peter and disabled Klara, she has lots of adventures. Source: MAL