Reese Witherspoon, who starred in the film, said she was "so heartbroken" over the shock death of her former co-star after it was revealed she died last month in Portland.
The family also added that Jessica had been suffering congestion symptoms and felt like she was coming down with a cold.
"While coping with this unexpected and tragic turn of events and planning for Oliver's future, the family is also faced with unexpected cremation, memorial, and probate expenses".
As reported by TMZ, Campbell visited her mother and aunt on December 29, following a regular day of work as a naturopathic physician.
In the film, she played Tammy Metzler, the sister of school jock Paul whose girlfriend leaves her to start seeing Paul.
More than $22,000 has been donated so far, including a $5,000 donation by Freaks and Geeks' executive producer, Judd Apatow. "I'm sending all my love to Jessica's family and loved ones". He said Election "was the first" big film "for both of us". Seen here, Jessica Campbell (as Tammy Metzler). "Jessica was so amusing and an incredible, thoughtful actress".
Campbell's professional website details how she long considered a career in traditional medicine, but after "some soul searching she realized that holistic medicine was what truly spoke to her". Her family did not think it was COVID-19, but an autopsy has not yet been concluded.