Can Fiance apply for I-485 based on her parents if she didn't get married?

[Iryna Di]

A girl (over 21) fall in love with US citizen, they lived together in other country and he made her a fiance visa after he moved back to US. Than he decided not to marry her. Her parents are green card holders.
Can her parents apply for I-485 for her while she is in USA on K1 visa?
If so, would that give her legal status after visa expires?
How long can it take to be processed?

I looked everywhere but didn't find an answer. Can you please help?

[newacct]

A girl (over 21) fall in love with US citizen, they lived together in other country and he made her a fiance visa after he moved back to US. Than he decided not to marry her. Her parents are green card holders.
Can her parents apply for I-485 for her while she is in USA on K1 visa?
If so, would that give her legal status after visa expires?
How long can it take to be processed?

I looked everywhere but didn't find an answer. Can you please help?

No. Someone who entered on K-1 is not eligible to do AOS except through marriage to the citizen who petitioned them.

Her parent can petition her. Note that it would be in the F2B category (unmarried over-21 child of permanent resident) which has a wait of about 7 years for people born in most countries (longer for people born in Mexico or the Philippines), and she cannot get married during this time. At the end of the wait, she will do Consular Processing abroad for an immigrant visa. She can only do AOS if she is in the US and in status at that time, which is unlikely.