I'm not sure what breed prolly a mix but I thought black chickens had dark earlobes this one is solid black looks like a Black astrolope but with white earlobes
Just typed 'black leghorn' in the search bar, and found a thread showing some black leghorns with truly yellow legs. Much better birds than what I had. She also might be a black Andalusian - I doubt Black Minorca because of the body type.