All her parents would need to do is convince a judge she isn't mentally fit. Then it's legal guardianship.
Similar thing happened to my aunt before she passed away. She lived in another province, had some medical issues related to schizophrenia, went to a hospital and came out "unfit" and placed under a court appointed legal guardian. Took her years but eventually she was able to fight it and be found competent, only to pass away about a month later.
@dancerxoxo123 I think you need to answer this question for yourself, not for us.
Do you want to be placed under your parents legal guardianship as an Adult? If the answer is no, then you'll be wanting to talk to a lawyer. The problem though is you still live at home, depending on how things play out you could potentially end up having to leave home. Would you be ok with that?
What I worry about it, is a potential scenario where your parents get legal guardianship, you stay with your boyfriend, get pregnant, and your parents decide on your behalf to terminate. Sounds to me like a nightmarish scenario.
As for your IQ don't let that worry you. I've known plenty of folks with similar scores that have lead perfectly happy and independent lives.