The 19-year-old spoke to activist and former journalist Nareen Shammo for a new BBC Arabic documentary, Slaves of the Caliphate, which will air on Saturday.
Hamshe said she was held by Isis militants for 28 days, who she says also killed her husband, father in-law and brother in-law.
|Hamshe and son|
“I can never forget when they separated the men and women from each other," she said. "It was very painful to witness women and girls being taken as war spoils.
“They forced the Yazidi girls to donate blood to Isis wounded fighters. Which God allows these acts?”
Another 21-year-old survivor recalled seeing women being repeatedly raped and tortured by militants.
A Yazidi teenager who was captured and held by Isis militants has claimed women are being forced to donate blood to save the lives of wounded fighters.
She told Ms Shammo: "I saw babies separated from their mothers. Some children were five and six years old when they were taken from their families."
"They killed our fathers, uncles and everyone. There is no horror I haven’t experienced. There is nothing worse than rape."
"One of the leaders took a 13 year-old girl to his house, locked the room and told his children she is a Yazidi girl who converted to Islam, that he will teach her how to pray and read the Koran. In fact he was raping her during that time. She told me she was there for three days and said ‘I was raped all that time'."
Hamshe said she fled her captors one night as they slept outside the room she was being held in.
“One night my baby was crying from thirst. I knocked at the door and saw all the guards sleeping outside. I took a bottle of water from them and I ran away with my baby and walked for four hours,” she said.
Hundreds of women and children were captured during the group’s rapid advance through northern Iraq earlier this year and have since been trafficked as sex slaves and forced into marriage.
The atrocities endured by Yazidi sex slaves was exposed more fully in an 87-page report released by Amnesty International in November, who found girls and women were repeatedly raped and sold as sex slaves.
EVEN CHILDREN WERE SOLD AS "GIFTS" TO ISIS FIGHTERS AND THEIR SUPPORTERS.
The abuse was so horrific that some of the women killed themselves or made attempts at ending their lives. The BBC estimates that just 300 Yazidi women have been released since August 2014 out of over 3000 captured.
Ms Shammo, who says she has tracked many kidnapped Yazidi women and works to help negotiate their return home, told the BBC Arabic investigation the accounts of transfusions are the first time she has heard of such a practice.
|Many Iraqi Yazidi women now face a terrifying future under Isis|
Ms Shammo uses mobile phones to contact women who have managed to hide devices from women.
She was filmed communicating with kidnapped women and at one point spoke to an Isis militant when he answered the phone of a captive, who told her: "They [Yazidi women] are in Isis' hands, they will convert to Islam and live under Isis protection."
Please pray for these women and girls. Pray for God to have mercy on them. Pray that many would be able to just walk away as Hamshe did.