She is not an Ameraucana. That is a specific breed, with specific traits, and she does not have them all. The most obvious point: Ameraucanas have muffs (fluffy feathers on the sides of the face), and she does not.
She might be an Easter Egger (sometimes misleadingly labeled as Americana or various other spellings that look similar to Ameraucana but are not quite right). Or she might be an Olive Egger.
It looks like she has a pea comb, so it is likely that she has some ancestors that were Ameraucanas, or Araucanas, or some of the birds that were ancestors of those two breeds.
But I think she most likely has Easter Egger parents, and Easter Egger grandparents, and Easter Egger ancestors for enough generations that nothing else can really be identified.
Easter Egger just means the chicken lays blue or green eggs, and does not look right for any specific breed. Olive Egger means the chicken lays dark green eggs ("olive" colored), and also does not look right for any specific breed.