It’s hard to believe she turns 70 next year.

And fun-loving Diane Keaton channelled her inner rock chick when she stepped out with her 20-year-old daughter Dexter in California on Monday.

The mother and daughter, who are rarely pictured together, dined out in the Brentwood area as they enjoyed a bit of quiet girl time.

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Girls’ day out: Diane Keaton, 69, channelled her inner rock chick when she stepped out with her 20-year-old daughter Dexter in California on Monday

Diane grinned from ear-to-ear as she trailed behind her daughter dressed in a black leather pencil skirt, matching ankle boots and a white jacket.

She accessorised her look with a chunky, studded waist belt and jazzed up her outfit with black, polka dot socks which stretched beyond her boots.

She rounded off her eccentric ensemble with round, tinted sunglasses and wore her silver hair in a sleek bob which swept across her face.

Dexter, meanwhile, embraced a much softer look, opting for a white and burgundy floral tea dress for her day out.

Double trouble: The mother and daughter, who are rarely pictured together, dined out in the Brentwood area as they enjoyed a bit of quiet girl time

Looking great: Diane grinned from ear-to-ear as she trailed behind her daughter dressed in a black leather pencil skirt, matching ankle boots and a white jacket

She teamed the flirty frock with heeled gladiator sandals and wore her chestnut hair in a straight style.

Both women held their phones in their hands and they marched down the street.

Diane, who has never married, adopted Dexter and her son Duke late in life.

And she says motherhood turned her world upside down at the ripe age of 50.

Speaking to The Independent earlier this month, she said: ‘[It] changed my life and made it so much more meaningful. It’s given me a purpose other than myself, which is really nice.’

And it’s clear to see her kids help her stay so young at heart.

‘I listen to a lot of pop music with my kids,’ she continues, listing Beyoncé, Rihanna and Kanye West as her favourites. ‘I just like the way they make music now.’

Family fun times: Diane, who has never married, adopted Dexter and her son Duke, now 15, late in life

Diane’s stars opposite Morgan Freeman in her new film Ruth & Alex, which is directed by Richard Loncraine.

She and Morgan play the titular septuagenarian couple who decide to sell up their Brooklyn apartment after four decades living there.

The hipsters are moving in and Freeman’s Alex is no longer capable of managing the five flights of stairs to their front door.

‘It’s all about whether we’re going to adjust to a different point in our life, and buy an apartment that has an elevator.

‘It’s a five-floor walk-up and he’s having a hard-time getting up the stairs! So that’s all the movie’s about really,’ she added.

Ruth and Alex is in cinemas and on demand now, courtesy of Signature Entertainment.

Still going strong: Diane’s stars opposite Morgan Freeman in her new film Ruth & Alex, which is directed by Gone Girl’s David Fincher