It's already been said, just stop giving her money, but play the long game, especially if you do genuinely get on with her. I'd say just see her socially (if you do like her company), but let her contact you.
If you go for a meal and it's a little expensive, ask her outright if she can chip something in. Suggest you are a little skint.
But never fuck her, paid or otherwise. Make up any excuse you want if she feels hard done by. New years resolution, you have medical problems, you've fell for someone else, whatever.
Then keep that up. Only let her contact you, and only see her for a meal or whatever, never fuck her, never give her any money. Eventually she might get desperate and just ask you for money. Just tell her you're skint, saving up for something, and you're sorry you can't help out, you've got to be strict with yourself.
If she keeps pestering you, you've every right to tell her to get lost and stop bothering you. You'd help her if you could, just not financially.
Let her go, don't fuck her, or ever give her money, but if you do get on with her, advise her. Help her in other ways, like if you can help her get a job somewhere or whatever.