She told Al Sabah that her son-in-law was also executed by IS - but not before his hands and feet were cut off - in 2014 when IS took control of Shirqat.
Al-Jumaily posts graphic photos of her work on Facebook. Among them, a picture of what appears to be her carrying a severed head; another showing two heads in a cooking pot; and another showing her standing over headless, burnt-out bodies.
Last week she led a group of 50 fighters into the Shirqat city centre and took control from IS, Iraqi media reports.
She told newspaper Al Sabah that she has killed 18 terrorists herself, and added: "We are fighting like a family".
Al-Jumaily, who is also a grandmother, said she had received death threats from the IS leadership - "including from (Abu Bakr) al-Baghdadi himself".
"I'm at the top of their most wanted list, even more than the Prime Minister," she said.
"Six times they tried to assassinate me. I have shrapnel in my head and legs, my ribs were broken, but all that didn't stop me from fighting," she told CNN, lifting her headscarf to show several scars.
She said her two daughters, aged 22 and 20, are trained to fight but are looking after their children.
Al-Jumaily's battle with jihadists dates back to 2004, when she starting working with Iraqi and coalition forces in the battle against al-Qaeda and later IS.
The militia leader said IS supporters had planted car bombs outside her home in 2006, 2009, 2010, and made three attempts on her life in 2013 and 2014.
"But all that didn't stop me from fighting," she said.
General Jamaa Anad, commander of Iraqi ground forces in Salahuddin province, told CNN they had provided her group with vehicles and weapons.
"She lost her brothers and husbands as martyrs," he said. "So out of revenge she formed her own force."