The best-selling British novelist died last week at age 77, after a secret seven-year battle with breast cancer.
"As Jackie said in her last interview, she did things her way," actress Joan Collins wrote in an essay for the UK's Mail on Sunday. "I celebrate the way she lived her life and, as she put it, the pleasure she gave to me and to so many people."
In the essay, Joan described getting a call from her younger sister telling her she had stage-four breast cancer and had known for seven years but didn't want to "burden" her older sister with her problems.
The actress also recalled memories from their childhood, Jackie's relationship with some of Joan's many husbands and her sister's love of pop culture and her three daughters.
"She will live on in the wonderful memories I have of her from our childhood and particularly from the last 15 years," Joan concluded the essay. "I feel her spirit, I hear her wonderful laugh and I see her all the time in the hundreds of photos of her sprinkled around my home. She wasn’t just a star -- to me she was an entire galaxy."
In her final interview just days before her death, Jackie told People magazine that she found a lump two years before she ever went to see a doctor and was diagnosed with stage-four cancer.
"I thought, 'I'm not dealing with this' because in my mind I decided it was benign," she told the magazine. "I've had to deal with losing my mother (to breast cancer), my husband (to prostate cancer) and my fiancé (to lung cancer) and I did not want to put pressure on everybody in the family. So I happily, happily went day by day."
She added, "That was my choice and maybe it was a foolish one, but it was my choice. Now I want to tell people it shouldn't be their choice."