Fan Theory on Jenny’s Death
Jenny’s death in the film was due to an unnamed disease and many speculate that it was because of AIDS. Jenny was a party girl for much of her young life, and her falling in with the hippie crowd led to her involvement in hard drugs and shared needles.
She was able to clean up her act and marry Forrest, living with their son Forrest Jr. in Alabama. A fan theory suggests that she only contracted HIV/AIDS after their son was born, which would explain why Forrest and their son both remain clear of the disease.