Girlfriend has to support parents+siblings and nephews? Big joke, I want to break up, please make a decision.

You can talk to her. I think you are right. Parents should support it, but others have the ability to manage it, and they can't manage it without it. This is reality.

If she is unreasonable, then she can choose to break up.

There is great pressure to marry a rural daughter-in-law. Whether she has a job or not means that you can support a large family in the future.

Sometimes the reality is overwhelming.

You talk to her about it. If she can understand better, break up if she doesn't understand.