Claire Mahan is the mother of Gia Mahan and she is divorced. She works at a diner. She and Gia live together in an apartment complex. She goes on a date with Danny Tanner in the episode "Claire and Present Danger". Since Danny met her in the episode "Making Out is Hard to Do", he has developed a crush on her.

Claire was born on August 14, 1956 in Fresno, California. She got married in 1976 to her husband and had her only child, Gia, on December 19, 1980. Claire and her husband got divorced in 1990.

Claire and Danny meet when Stephanie (unknowingly) goes to Gia's unsupervised make-out party. They get off to a rough start, with Danny blaming Claire for not knowing her daughter was hosting a party. However, after softening up, he admits that he blamed her because he did not want to blame himself for not knowing Stephanie was going to a make-out party. They go out for coffee—explained by Stephanie to Gia that for people their age, going out for coffee is a date—and then start dating. This makes both Stephanie and Gia excited, believing they could possibly become sisters. However, after all this sister talk, Michelle feels left out and acts like the complete opposite of herself, wearing heavy-metal clothes and a ton of make-up, and even asking Claire for a cigarette. She and Danny make up, and allows Claire and Danny to dance.