She is best known for her scene when she challenges Jack (played by Leonardo DiCaprio) about his new love interest (Kate Winslet).
When Rose decided to see what life was like in third class on the doomed ship, she rudely interrupted the little girl's dance with Jack.
While the curly haired brunette was initially furious to have the heartthrob stolen from her, hearts melted when she was told she was still "his best girl".
Cora was also set to appear in another heartwarming moment with Jack, which would see him draw her on the deck of the ship, but it was unfortunately deleted from the final cut.
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Jack called Cora his 'best girl' in the iconic James Cameron film
Cora's dance with Jack was rudely interrupted by Rose
Child stars then & now
Mon, December 12, 2016
These child stars are all grown up. From Daniel Radcliffe, to the cast of Willy Wonka, see the children who aged gracefully into adulthood.
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I'll Be Home For Christmas heart throb Jonathan Taylor Thomas in 2000 and now
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Jack Dawson told Cora Cartmell she was his best girl
Now, Alex Owens who played the youngster, is unrecognisable and looks world's away from her Titanic character.
She has continued to pursue a career in acting and has also been busy writing a sketch comedy that she hopes to start producing very soon.
It comes after she graduated from California State University with a degree in writing.
And, while Titanic may have been released in cinemas 20 years ago, she still has fond memories of working with Leo and Kate.
She recently shared a throwback snap of herself and her younger sister hanging out with the Oscar winners in between takes on her Instagram page.
Alex Owens played Cora Cartmell in the 1997 film
Alex shared a throwback snap of herself with Kate Winslet and Leonardo DiCaprio
Alexa Owens said she remembers her time on set with Leo and Kate fondly
Speaking about her time filming the deleted scene between Cora and Jack, she told Buzzfeed that she remembered "sitting with Leonardo DiCaprio, and we were drawing in his sketchbook… it was three hours [of takes] and, in between, just hanging out and drawing pictures with Leo".
Alex added that despite the movie being released two decades ago, she still loves it when people recognise her.
She explained that a waiter noticed her when she was drinking at a bar with friends and admitted: "I was going to walk up to you and just say, 'You're still my best girl, Cora,' but I didn't want to be wrong and then feel like an idiot."
The star said if the waiter had delivered the now infamous line then it would have "made her entire life".