Kimberly Guilfoyle, Donald Trump Jr.'s partner and a top fundraising official for the Trump campaign, tested positive for the coronavirus on Friday, The New York Times reports.Why it matters: Guilfoyle is the third person in President Trump’s circle known to have contracted the coronavirus. Vice President Mike Pence's press secretary tested positive, as did a personal valet who served Trump food.The state of play: Guilfoyle was set to attend the president's Independence Day event in South Dakota, but canceled. She did not travel with Trump on Air Force One, according to the Times. Donald Trump Jr. has tested negative for the virus, but will be self-isolating as a precaution and has canceled his events.What they're saying: Sergio Gor, the chief of staff for the Trump Victory Finance Committee, said, Guilfoyle “was immediately isolated to limit any exposure... She’s doing well, and will be retested to ensure the diagnosis is correct since she’s asymptomatic, but as a precaution will cancel all upcoming events.”Go deeper: Six Trump campaign staffers test positive for coronavirus ahead of Tulsa rally