There is no definitive answer to this question as the meaning of petty can vary depending on who you ask. Generally speaking, however, petty for a girl usually refers to someone who is excessively concerned with trivial matters or someone who constantly finds fault with others. Additionally, the term could also be used to describe a girl who is overly dramatic or prone to fits of jealousy. Ultimately, whether or not something is considered petty is often subjective and up for interpretation.