Ron Howard praised the late Cindy William's "spark and energy"

The 68-year-old director told 'Entertainment Tonight': "It was a shocker to hear of Cindy's passing. I remember her life spark and her energy. I saw her last year in Palm Springs at an event and still saw that sparkle in her eyes. It's so hard to imagine that she's gone."

Jamie labelled the ex 'Laverne and Shirley' star a "natural comedian" as she lamented on Hollywood's tragic loss.

The 64-year-old actress wrote on a black and white image of Cindy: "Cindy was AMAZING! Such a great, natural comedian. So wide open. Such a sad loss."

Rosario added on Twitter: "Singing this song with so much gratitude for both of you ladies. Absolute gems. United again... Rest in Paradise Cindy Williams."

Director Meg Foster acknowledged the contribution Cindy made to her 2012 movie, 'Stealing Roses'.

She wrote: "I had the privilege to direct Cindy Williams in an indie film called Stealing Roses (with John Heard). She was talented, kind and so funny. RIP Cindy."

Henry Winkler, her 'Happy Days' co-star mused about being "grateful" to have known her.

The 77-year-old actor said: "Cindy has been my friend and professional colleague since I met her on the set of 'Happy Days' in 1975. Not once have I ever been in her presence when she wasn't gracious, thoughtful and kind. Cindy's talent was limitless. There was not a genre she could not conquer. I am so glad I knew her."

The tributes came after Cindy's family announced she had passed away in a statement that highlighted her "glittering spirit".

Their representative said: "The passing of our kind, hilarious mother, Cindy Williams, has brought us insurmountable sadness that could never truly be expressed. Knowing and loving her has been our joy and privilege. She was one of a kind, beautiful, generous and possessed a brilliant sense of humor and a glittering spirit that everyone loved. We have always been, and will remain, SO proud of her for many things...her lifelong mission to rescue animals, her prolific artistry, her faith, and most of all, her ability to make the world laugh!"