Theresa Hackett Net Worth: Undisclosed. Try again later. According to personal friends, she accepted her fate with equanimity and dignity, dying at the age of just 49 in a hospital in Encino, California, in October 1983. Find more celebrity bio and other think check onallcelebritywiki.com. 'key' : '9979f54672ca788f6b7068e52c23936c', Joan Hackett age is 88 Years in 2022, 89 Years in 2023, 90 Years in 2024 and 91 Years old in 2025. document.write('