In ACT 1 Scene iii when the Nurse speaks forever telling all she knows about Juliet to audience and Lady Capulet this is considered a soliloquy because thinks no one listening?

The Nurse's speech in Act 1 Scene iii is not a soliloquy because she is not alone. She is speaking to Lady Capulet, and therefore, she knows someone is listening. A soliloquy is a speech given by a character while alone on stage, in order to express their thoughts and feelings to the audience.