Well, she's a pullet, but not a Marans. Marans should only have pink/white legs. I would guess that you have a Blue Jersey Giant mix or Australorp mix on your hands.
Are the bottoms of her feet yellow or white? White would indicate a Lorp, and yellow a Giant. Perhaps someone crossed one of the two with a Marans.
edited to add: This one is really nagging at me lol. Another possibility is a Langshan, it has some really nice long legs.