Shirley Jones turns 90! The Partridge Family star whisked up to mountain resort by sons Shaun, Patrick and Ryan Cassidy to 'get happy' at birthday celebration

The Partridge Family star Shirley Jones turned 90 years old this Easter, celebrating the milestone with her three sons and her grandchildren.

Her sons Shaun Cassidy, 65, Patrick Cassidy, 62, and Ryan Cassidy, 58, whisked her up to a luxurious mountain resort to ring in the occasion.

One night before the big day, Shirley enjoyed a party where she was decked out in a tiara and a beauty queen sash reading: '90 & Fabulous.'

She gathered together with her sons for a heart-warming picture, bringing back memories of The Partridge Family catchphrase: 'C'mon, get happy!'

Shaun proudly posted the photo to his Instagram the next day, writing: 'Happy 90th birthday to Miss Pittsburgh! What an incredible night.' 

The Partridge Family star Shirley Jones turned 90 years old this Easter, celebrating with her sons (from left) Patrick Cassidy, 62, Shaun Cassidy, 65, and Ryan Cassidy, 58

The Partridge Family star Shirley Jones turned 90 years old this Easter, celebrating with her sons (from left) Patrick Cassidy, 62, Shaun Cassidy, 65, and Ryan Cassidy, 58

Shirley (center) is pictured in a 1972 publicity shot for with (from left) Jeremy Gelbwaks, Danny Bonaduce, Suzanne Crough, David Cassidy and Susan Dey

Shirley (center) is pictured in a 1972 publicity shot for with (from left) Jeremy Gelbwaks, Danny Bonaduce, Suzanne Crough, David Cassidy and Susan Dey

The caption was a reference to the fact that Shirley was indeed crowned Miss Pittsburgh in 1952 at the age of 18, kicking off her showbiz career.

She started off as a Broadway chorus girl working for Rodgers and Hammerstein, the writing and producing team behind such musicals as The Sound Of Music.

From there, she landed the lead role in the 1955 film of Oklahoma!, the Rodgers and Hammerstein show that had revolutionized Broadway over a decade earlier.

Although she largely took good-girl roles in movie musicals like Carousel and The Music Man, she won her Oscar playing against type in the 1960 drama Elmer Gantry.

In that film, she featured as Lulu, a minister's daughter who turns to prostitution after being seduced and deserted by a con man played by Burt Lancaster. 

However, her most famous role was that of a widowed mother of seven on The Partridge Family, the 1970s sitcom that became an emblem of its decade.

One of her children was played by her real life stepson David Cassidy, who died of liver failure at aged 67 in 2017 after struggling with a drinking problem. 

Shirley had all three of her biological sons with David's father Jack Cassidy, a Broadway star known for his silkily deep voice and irresistible suavity. 

One of her early roles was the 1955 film of Oklahoma!, the Rodgers and Hammerstein show that had revolutionized Broadway over a decade earlier; pictured with Gordon Mcrae

One of her early roles was the 1955 film of Oklahoma!, the Rodgers and Hammerstein show that had revolutionized Broadway over a decade earlier; pictured with Gordon Mcrae

She won her Oscar for Elmer Gantry, portraying a minister's daughter who turns to prostitution after being seduced and deserted by a con man played by Burt Lancaster

She won her Oscar for Elmer Gantry, portraying a minister's daughter who turns to prostitution after being seduced and deserted by a con man played by Burt Lancaster

One of her children on The Partridge Family was played by her real life stepson David Cassidy, who died of liver failure at aged 67 in 2017; the pair are pictured in 1972

One of her children on The Partridge Family was played by her real life stepson David Cassidy, who died of liver failure at aged 67 in 2017; the pair are pictured in 1972

She was only 20 years old when she met Jack, whom she described as her 'Svengali' and remained married to for 18 years.

They enjoyed an electric chemistry in the bedroom, helped along by what she described as her 'highly sexed' nature that made it easy for her to have orgasms - as well as the fact that Jack was, according to her, handsomely endowed.

Jack was himself a bisexual who once indulged in a liaison with Broadway songwriter Cole Porter, and he urged Shirley to 'experience everything' sexually.

The couple frequently appeared onstage together and collaborated on eight albums, but offstage their marriage eventually frayed. 

Jack, a bipolar alcoholic, had trouble coping with the fact that Shirley's fame and success eclipsed his during her years on The Partridge Family.

'I mean, he was my knight in shining armor, he was the love of my life,' Shirley told ABC. 'I was the breadwinner in the family and it was very difficult for him.'

They divorced in 1974, and the following year he suffered a horrific death after falling asleep on the sofa with a cigarette in his hand and setting his penthouse on fire. 

Just hours before the tragic incident, Shirley had turned down an invitation from him to meet him at his apartment for a drink. 

Shirley had all three of her biological sons with David's father Jack Cassidy, a Broadway star known for his silkily deep voice and irresistible suavity; pictured 1959

Shirley had all three of her biological sons with David's father Jack Cassidy, a Broadway star known for his silkily deep voice and irresistible suavity; pictured 1959

Shirley later enjoyed a long marriage to agent and 'celebrity broker' Marty Ingels from 1977 until he died in 2015 of a stroke aged 79.

However she retained her feelings for Jack, remarking later that he 'wanted to come back (to me) right up to the day he died. And I wanted him. That's the terrible part.'

She confessed: 'Much as I love Marty and have a wonderful relationship - I'd say this with Marty sitting here - I'm not sure if Jack were alive I'd be married to Marty.' 

Her television career continued through the decades, ranging from an Emmy-nominated performance in the Hallmark movie Hidden Places to a recurring guest shot on The Drew Carey Show to a run in Days Of Our Lives.

About a decade ago, Katie Couric asked Shirley about her secret to staying youthful and was stunned by her frank answer: 'Masturbation! Sex keeps you young no matter what. The feelings of it keep you going.'