Shirley MacLaine celebrates her landmark 90th birthday with low-key lunch in Malibu... ahead of the release of Oscar-winner's new memoir The Wall of Life

The legendary Shirley MacLaine kicked off her 90th birthday celebrations on Thursday with a dressed-down lunch in Malibu.

The  Oscar winner was sporting a trucker cap over her white hair and she wore black  glasses for her low-key celebrations.

'I have my friends and I am really healthy,' Shirley declared to People on Wednesday.

'I started my dance training at age three and stopped at about 67. It taught me discipline, loving music, working with people and dealing with pain.'

MacLaine was joined by a blonde female companion ahead of her intimate birthday dinner with friends: 'We're getting together and I hope to eat something good.'

The legendary Shirley MacLaine kicked off her 90th birthday celebrations on Thursday with a dressed-down lunch in Malibu 

The Oscar winner was sporting a trucker cap over her white hair and she wore black glasses for her low-key celebrations 

The Only Murders in the Building guest star just announced that Crown will publish her 288-page memoir The Wall of Life: Pictures and Stories from This Marvelous Lifetime on October 22.

'I have lived a wonderful life and I wanted to share it. All of the photos brought back such wonderful memories,' Shirley said.

'About 45 years ago, I put 10 or so framed photographs of friends and family and people I've worked with all grouped together on a living room wall. Everyone who came over loved to look at this montage, and so The Wall of Life was born. I'm pleased to share a selection of these photos — and some of the stories behind them — in this book.'

The $35 book will include stories from MacLaine's seven-decade career, advice to Elvis Presley, insight into Jack Nicholson and the Dalai Lama, as well as her childhood growing up alongside brother Warren Beatty.

The Virginia-born redhead moved to New York City at age 16 in 1950 and she got her big break in 1954 as a stand-in in Broadway's The Pajama Game before landing roles in Alfred Hitchcock's 1955 comedy The Trouble with Harry and Billy Wilder's 1960 rom-com The Apartment.

After earning five Academy Award nominations, Shirley finally won Oscar gold for her searing portrayal of Houston socialite Aurora Greenway, whose daughter battles cancer, in James L. Brooks' 1983 dramedy Terms of Endearment.

MacLaine is also famed for her performances in Sweet Charity (1969), The Turning Point (1977), Steel Magnolias (1989), Postcards from the Edge (1990), etc.

The Emmy winner - who was the only female Rat Packer - loved and left the likes of her What a Way to Go leading man Robert Mitchum as well as Prime Minister Olof Palme of Sweden, novelist Pete Hamill, and French heartthrob Yves Montand.

Shirley was joined by a blonde female companion ahead of her intimate birthday dinner with friends: 'We're getting together and I hope to eat something good'

MacLaine (born MacLean Beaty) just announced that Crown will publish her 288-page memoir The Wall of Life: Pictures and Stories from This Marvelous Lifetime on October 22

Shirley - who lowered the price of her Plaza Blanca Ranch in New Mexico to $4.3M last October - is notoriously estranged from her daughter Sachi Parker, who penned a 2013 scathing tell-all titled Lucky Me.

MacLaine gave birth to her only child during her open 28-year marriage to the late Steve Parker, which ended in 1982.

The 67-year-old actress has two adult children - son Frank, 27; and daughter Arin, 25 - from her 18-year marriage to investment banker Frank Murray, which ended in 2011.

The NY Times bestselling author has previously published 20 books including memoirs as well as tomes about metaphysics, spirituality, and reincarnation.

Shirley will soon fly to Atlantic City in New Jersey to film her role as 'a sprightly woman in her twilight years who strikes up an unlikely friendship with a homeless man' in Brad Furman's drama People Not Places.

'It's a wonderful script and we are getting ready to start and will see what happens,' MacLaine gushed.

'[I'm so grateful] that I can keep working.'

The Downton Abbey scene stealer was honored with the Film Society of Lincoln Center Tribute in 1995, the Cecil B. DeMille Award in 1998, the AFI Life Achievement Award in 2012, and the Kennedy Center Honor in 2013.

The $35 book will include stories from the Only Murders in the Building guest star's seven-decade career, advice to Elvis Presley, insight into Jack Nicholson and the Dalai Lama, as well as her childhood growing up alongside brother Warren Beatty (R, pictured in 1966)

Shirley moved to New York City at age 16 in 1950 and she got her big break in 1954 as a stand-in in Broadway's The Pajama Game before landing roles in Alfred Hitchcock's 1955 comedy The Trouble with Harry and Billy Wilder's 1960 rom-com The Apartment (pictured)

After earning five Academy Award nominations, MacLaine finally won Oscar gold for her searing portrayal of Houston socialite Aurora Greenway, whose daughter battles cancer, in James L. Brooks' 1983 dramedy Terms of Endearment

The Virginia-born redhead is also famed for her performances in Sweet Charity, The Turning Point, Steel Magnolias, Postcards from the Edge (pictured in 1990), etc.

Shirley - who was the only female Rat Packer - loved and left the likes of her What a Way to Go leading man Robert Mitchum (R, pictured in 1964) as well as Prime Minister Olof Palme of Sweden, novelist Pete Hamill, and French heartthrob Yves Montand

MacLaine will soon fly to Atlantic City in New Jersey to film her role as 'a sprightly woman in her twilight years who strikes up an unlikely friendship with a homeless man' in Brad Furman's (L, pictured in 2012) drama People Not Places