My girls won't eat cabbage, broccoli or celery, but will eat most other greenery. If you plan on keeping her, get some books out the library and see how easy it is. We've had our girls for 2 years now and the eggs are the best ever. If your girl's comb is pale pink and small, she is still young and will probably not lay yet, but it won't be very long. You can keep chickens on hard standing, they just need somewhere to scratch, but she will need to be enclosed.
Let us know how you are getting on.