The phrase "new girl" can often seem limiting and one-dimensional. A few alternative synonyms could bring new possibilities to mind. You could refer to her as a novice, introducing a sense of learning and potential. A newcomer, emphasizing that this girl is new to the community or group. A fresh face can imply a sense of excitement and originality while a neophyte emphasizes the newness of the learning experience. If you want to add a bit of fun or whimsy, a fledgling suggests a baby bird taking flight or a protege alludes to a promising new talent. Ultimately, there are many ways to capture the essence of a new girl in different contexts.