Police in Osan said they would be seeking an arrest warrant to charge the woman with negligent arson and involuntary manslaughter.
The mother fell to her death after she and her husband opened their window and tried to climb across to the neighbouring building.
She was taken to hospital where she was pronounced dead at around 10.40am local time.
In 2016, an American man started a fire at his home while using bug spray and a lighter to create a flamethrower to kill cockroaches.
And in 2018, an Australian man set fire to his kitchen, also while trying to kill a cockroach.
Sign up to Herald Premium Editor’s Picks, delivered straight to your inbox every Friday. Editor-in-Chief Murray Kirkness picks the week’s best features, interviews and investigations. Sign up for Herald Premium here.