While the whole kidnapping is an exceptionally scummy move...
Well, she's still 8 so... let's just say it's still very much possibile to force her into her supposed destiny...
It happens all the time IRL. And religious fundamentalists are not exactly know for their piety.
https://www.savethechildren.org/us/charity-stories/child-soldiers
https://www.unicef.org/protection/children-recruited-by-armed-forces
https://en.wikipedia.org/wiki/Children_in_the_military
Some quotes from the links above:
Child soldiers are boys and girls who are often abducted and used as combatants, forced to act as human shields or conduct executions, deployed as suicide bombers, or used to make or transport explosives. Other roles include working as guards, spies, messengers, porters, cooks or domestic servants.
Many children, more often girls, are subjected to sexual abuse and exploitation, while some are forced into child marriage as “brides” for fighters. Girls forcibly married in this way are frequently abandoned, divorced or left widowed, if they’re not killed or maimed themselves.
Throughout history, children have been recruited, often by force, and used in military campaigns. Child soldiers may be considered cheaper to recruit and train, more vulnerable to exploitation and abuse, or strategically useful – such as the girls used for the horrific suicide attacks by Boko Haram in Nigeria.
