Or she’s a spy for the three guys kicked out.
Nice plot twist!
She may be related to one of them, sexually abused and now imprinted on them or simply have family under their control.
From the criminals point of view, she’s perfect. She’s young enough that the Alexandria folks say “oh, she’s a kid, save her” and to be given freedom to explore as a child. Anyone who expects her to act as a junior adult will still give her benefit of the doubt for her age, her size and gender.
Her three weeks without saying anything looks like shell shock, an excuse to wander without giving excuses or have people talk to her for hours about everything to try to draw her out.
Or shes a spy for the three guys kicked out