US Hostage Gave Up Chance to Escape to Help Girls Kayla Mueller 'was like a mother figure to them' By Michael Harthorne, Newser Staff Posted Aug 15, 2015 3:15 PM CDT 44 comments Comments A fellow hostage claims Kayla Mueller, seen here in 2013, refused to escape with her and her sister in order to give the two young girls a better chance for freedom. (AP Photo/The Daily Courier, Matt Hinshaw, File) (Newser) – Despite being sexually abused by the leader of ISIS over a period of 18 months, US hostage Kayla Mueller is said to have turned down a opportunity to escape in order to give two young girls a better chance to survive, the Independent reports. A 14-year-old Yazidi girl who was held hostage with Mueller for a few months says she and her sister asked Mueller to escape with them in October, but Mueller turned them down, afraid her foreign appearance would jeopardize their safety. "Kayla tried to protect these young girls," Mueller's mother tells the AP. "She was like a mother figure to them." The girls made it out. Mueller, an aid worker who was captured in Syria in 2013, was killed this year. The Yazidi teen says Mueller was kept as the property of the ISIS leader, who "married her by force" and would sexually abuse her whenever he visited the home that served as her prison. During this time, Mueller wrote in a letter that she "formed a bond of love and support" with her fellow hostages. ISIS had demanded ransom and the release of one of their supporters in return for Mueller's freedom, but the US government refused the terms. The girls who escaped were members of the Yazidi, a minority group victimized by ISIS following the return of institutionalized slavery.