Frances Harriet Gallagher or Franny (briefly Harry) was born on the Gallagher family's kitchen table in episode "Paradise Lost". She is the daughter of Debbie Gallagher and Derek Delgado. Despite her mother's young age, she was a planned baby, but only from her mother's side. Debbie lied to Derek, about being on the pill, hoping to create a "happy family" with him.

Derek left Chicago to live in Florida with his grandmother, as he felt trapped by Debbie.

She was kidnapped by her father's relatives, but fortunately, the kidnapping was short-lived, and she was quickly brought back by Monica.

In season 8, she walks her first steps thanks to her grandfather Frank Gallagher (US).