Great question and this comes up a lot. Check out this unaccompanied youth eligibility flowchart and then please feel free to respond back with further questions. Thanks!!
https://nche.ed.gov/wp-content/uploads/2020/05/Handout-UHY-Flowchart.pdf
This was helpful as I just had conversation with admin about a student who is living with boyfriend and family. She has strained relationship with parents and admin say she does not fall under unaccompanied unless family says they kicked her out or something similar. If she voluntarily leaves the home then she does not qualify. What are your thoughts?