I'm a Big Girl Now was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 television series that ran one season during the strike-shortened 1980-1981 season. The series starred Diana Canova as Diana Cassidy and Danny Thomas

Danny Thomas

Danny Thomas was an American nightclub comedian and television and film actor, best known for starring in the television sitcom Make Room for Daddy . He was also the founder of St. Jude Children's Research Hospital...

 as Dr. Benjamin Douglass with not yet famous Martin Short

Martin Short

Martin Hayter Short, CM is a Canadian actor, comedian, writer, singer and producer. He is best-known for his comedy work, particularly on the TV programs SCTV and Saturday Night Live...

.

The show dealt with Diana and her young daughter moving back home with her father, Benjamin and his teenage son after her divorce.

The theme song, I'm a Big Girl Now, words by Leslie Bricusse

Leslie Bricusse

Leslie Bricusse is an English composer, lyricist, and playwright.Although best known for his partnership with Anthony Newley, Bricusse has worked with many other composers. He was educated at University College School in London and Gonville and Caius College, Cambridge...

 and music by George Aliceson Tipton, was sung by Canova.