All of you people who say she is wrong to sue are wrong. She started employment there with the expectation of being able to wear the pants and shirts as the uniform. This is an implied contract. The company has no right to change the contract without her approval. The way for the company to handle it would have been to require all new hires to wear the new uniform and the old hires could go either way as they saw fit. Eventually they would have all the girls wearing the new uniforms.
To sum it up. She had a contract, they violated it without her agreement. She will win in court, especially in view of the way they cut her hours vindictively and then dismissed her without cause.