The style expert and reality star revealed to Madame Noir last year that she was diagnosed with stage-three bile duct cancer, also known as cholangiocarcinoma – a rare cancer affecting the liver – at age 34.
"I realized that it was hard for my family and friends," she told the publication then. "I'm not afraid to go to heaven, but I would like to stay on earth if I can.
"If it's my time to go, then I can say that I had a great life."
The star also spent time in various editor positions at Essence , InStyle and Glamour magazines, according to Essence.
"She very much wanted to keep her diagnosis private. She didn't want people to treat her differently or feel sorry for her or treat her like she was sick," her costar Demetria Lucas D'Oyley tells PEOPLE. "Whenever she was out she was the same Daisy, just bubbly, full of energy. You'd see the behind the scenes sometimes on the show of her getting tired or going outside."
She says "everyone is devastated".
"She was very well known and very well loved across many circles, but she was a Brooklyn girl through and through," says D'Oyley. "Everyone's got a story, a picture a beautiful memory of her and they all say the same thing. She was such a bright light, a beautiful spirit, bubbly, positive."
Bravo also mourned her in a statement.
"We are devastated to learn that Daisy Lewellyn from Bravo's Blood, Sweat & Heels has passed away this morning after a battle with a rare form of cancer," Bravo said in a statement to PEOPLE. "Daisy passed on in peace and filled with joy, surrounded by her family and friends. We are all saddened to lose this wonderful woman. Our thoughts and deepest sympathy is expressed."
Lewellyn's Blood, Sweat and Heels costars took to social media to send condolences amid the news.
"I literally dreamed of her last nite ... perhaps it was as she was saying goodbye to all of us," Melyssa Ford captioned an Instagram photo of herself with Lewellyn. "The shock is wearing off and full blown grief is setting in. I cannot believe Daisy is gone. My heart breaks for her family. Her light and spirit will be sorely missed."
Brie Bythewood tweeted: Sending my prayers and condolences to the family of @daisylewellyn. May she rest comfortably in the hands of God. RIP you stylish beauty xo."