Was there any medical evidence she wasn't insane?
Her findagrave account says two physicians certified her insane, when she was released from asylum it was as incurably insane, so those asylum physicians must have concured.
This passage is curious too "She married Theophilus Packard at Shelburne, Massachusetts in 1839. After twenty-one years of married life she was taken to the insane asylum at Jacksonville, Illinois, where she remained three years. Her mind being fully restored, she determined to devote the rest of her life to working for corrective legislation for the insane."
Wouldn't that imply she had suffered a real episode of illness?