I think she's moderately cognitively impaired (IQ 70-90). In ye olden days, people like her were labeled "slow" and made to do manual labor and/or live off the charity of others. These days, it's trickier. People with moderate cognitive impairment are technically capable of living independently - they can read, write, shower, use public transit, make change - but are incapable of higher-level functioning. They can't work a normal job. They can't keep a schedule. Making a doctor's appointment or keeping an apartment clean (hi, Colt) is like climbing Everest. They just can't do it.
People like this are extremely vulnerable. They're extremely likely to be exploited and abused. Also, because they're semi-functional, they often slip through cracks in the system. If they're normal enough, they may be allowed to live on their own, no matter how innocent or gullible. Concerned parents are helpless to reign them in.
The story of Gemma is a great example. A cognitively impaired, but semi-functional girl is given her own government apartment, is used by drug dealers to store their goods, is eventually brutally tortured and killed by her beloved "friends."
tl;dr If Colt had just 5 fewer IQ points, she'd be in a group home, with the legal standing of a child, and her tits and hormones intact. Sad.