Katie thanked everyone for the outpouring of love and support during the difficult time, and said her father's final words will be a reminder to share her gratitude to those she loves and to never waste another minute.
David Cassidy died at age 67 on Tuesday after he was hospitalized with organ failure in Florida.
He skyrocketed to fame in the 1970s as he starred on TV's "The Partridge Family," becoming a singing superstar at age 20 and one of the biggest teen idols of the era. He was three years old when he decided he wanted to act, after seeing his dad, actor Jack Cassidy, in a Broadway musical.
As a teen, he landed a few small roles on television and Broadway before he was cast as Keith Partridge in the musical sitcom.
His real-life stepmother, Shirley Jones, was cast as his TV mother, Shirley Partridge. Neither knew the other had been cast until they showed up to work.
The ABC show lasted for 98 episodes over four seasons. During that time, Cassidy also put out four solo albums and broke box-office records touring the world as a singer.
His song "I Think I Love You" spent three weeks on the charts at No. 1. The song was released in late 1970 and became the year's best-selling single, beating out the Beatles' "Let It Be."