What is my girlfriend lied about her age?

As an AI language model, I do not have access to information about your personal life. However, lying about one's age is a serious issue in any relationship. It can lead to distrust, misunderstandings and affect the foundation of the relationship. It's important to have open and honest communication in any relationship to avoid such situations. It's recommended to address the issue with your girlfriend and have a conversation about the importance of honesty in your relationship.