Jacobs also said Depp was in such "financial desperation" in January 2016 that he came to the agency and asked for $20 million.
"The question was not asked as a loan," she said.
Jacobs said her partners told Depp the company was "not a bank" but they did help him secure a loan through Bank of America.
Josh Mandel, Depp's former business manager, was also asked about the actor's financial circumstances.
Mandel said he had become "extremely concerned" about Depp's financial situation in 2015.
There were "constant" conversations with Depp about curbing his spending, he said, but it "never seemed to happen."
"There was no followup," he said.
"It became clear over time that there were issues with alcohol and drugs," he said. "And that translated into more erratic behaviour."
Depp was spending $300,000 a month on full-time staff at one point and another $100,000 a month on a doctor and nurses employed to ensure his sobriety, he said.
Mandel estimated that Depp made around $600 million during the decades that he represented him.
Mandel was fired by Depp in 2016 and subsequently sued by the actor. They settled the case in 2018.
Jacobs was also fired by Depp in 2016.
Asked why Depp fired her, Jacobs said: "I really don't know. All I know is that he terminated essentially everyone in his life."
Depp's lawyers have put experts on the stand who testified that the actor lost millions because of the domestic abuse accusations, including a $22.5-million payday for a sixth installment of "Pirates."
Depp filed the defamation complaint in the United States after losing a separate libel case in London in November 2020 that he brought against The Sun for calling him a "wife-beater."
Depp, a three-time Oscar nominee, and Heard met in 2009 on the set of "The Rum Diary" and were married in February 2015. Their divorce was finalized two years later.
Judge Penney Azcarate has scheduled closing arguments in the case for May 27, after which it will go to the jury.
