Skilled worker - want to leave job but stay in the UK

Hi I'm Dan.

My girlfriend is from Bangladesh but she went to uni in Australia and lived there for 10 years. She then came to the UK on the 2 year visa, where we met. After 2 years her work sponsored her as a skilled worker for the extra 3 years. We are 1 year into those extra 3 years but she is not enjoying her job at all and really want to leave. We have been living together for just over a year and are aware that once we have lived together for 2 years we can apply for a visa but that is 9 months away and she really can't stay in her job much longer.

Barring getting a new job where they would sponsor her and barring getting married, what are our options?

Any help would be greatly appreciated, thanks.

Only other option is study route