She's just trying to 'earn a living'. [=to earn the money needed for food, clothing, etc.]
He will do anything to 'earn his keep'. [=to earn what is needed to support himself]
He 'earned/won his spurs' by doubling the company's profits in the past year.
(..) - Are you listening to me? - Yeah. Do you like Little Miss Thing sucking on your cock? Yes. Yes, I do. So earn it. I'm getting the feeling... ...we got a cop in my crew. Yeah, I know, I'm kind of getting that feeling too. He's one of yours. Inside. (..)2006 The Departed
(..) You do good in school? - Yeah. - That's good. I did too. They call that a paradox. Just keep it. Buy yourself some makeup. You ever wanna earn a little extra money, you come by L Street. You know where I am on L Street? Good. - Good boy. - Thanks. (..)2006 The Departed