"Prior to the flight, she had a couple of outbursts saying she was being treated wrong.
Some things with the government - personal and political," passenger Terrance Franklin told ABC13. "Once we got in the air, that's when it all started again. She was walking back and forth. I knew something wasn't right."
The woman was subdued by an off-duty officer from Cleveland who was also on-board the flight, and was restrained until authorities removed her upon landing.
According to the Houston Chronicle, Southwest Airlines confirmed in a statement that flight 4519 was diverted to Corpus Christi International Airport after flight attendants notified the captain of a "potential threat" in the cabin.
"Following an uneventful landing, local authorities met the aircraft at a gate and removed the disruptive passenger," the airline said.
But Kristy Gillentine, a former journalist and another passenger on the flight, said on Twitter that the "erratic" passenger should never have even been allowed to board.
The passenger was questioned by authorities but has not been formally charged with any crime.
It is understood that the FBI is now investigating the incident.