Johnson and the Hilton sisters grew up together and Nicky Hilton was Ava's godmother. Paris expressed her sorrow over Johnson's death on her Twitter page Tuesday. "In bed crying, looking at baby pictures of Casey, Nicky and I. I feel so upset. I feel like I've lost a sister. My heart is broken," she wrote.
Hilton once asked Johnson to co-star on her reality show "The Simple Life." Johnson turned it down and Nicole Richie was cast instead. Baker believes Johnson regretted it.
"I remember her saying, 'People think I'm this crazy party girl, but I'm a mom, a single mom,'" Baker recalled. "She also recognized that she had a crazy life, bopping around from this house to that house. She appeared to me as someone who was unstable. She seemed to be her own worse enemy."
Johnson most recently made headlines in December when Tequila announced their engagement in an Internet video while sporting a 17-carat diamond and bragging "My baby is a billionaire." Tequila, who also dated Semel, appeared to be a recent addition to Johnson's life.
"When I spoke to her about a month ago, Tila was not in the picture," Grubman said.
Tequila may have been the last to see Johnson. The reality star told TMZ Monday evening that the two had fought last week and that she was unable to reach Johnson Dec. 29 after she left her dogs at Tequila's house. Tequila told TMZ that Johnson's phone had been turned off ever since.
"I can't stop these haunting visions of her and I," Tequila tweeted early Tuesday morning. "We made such a lovely couple, only beginning to spend the rest of our lives together..."