First of all, keep calm about the girl's feedback and try to understand her feelings. Listening is the foundation for effective communication, and by paying attention to her words and emotions, you can understand why she feels perfunctory.
In your response, reflect honestly on your actions. Ask yourself if you don't seem focused enough or don't show enough concern in your communication. Possible misunderstandings need to be confronted with sincerity, not avoided.
Apologize in a sincere manner, tell her that you didn't mean to be perfunctory, and that you're sorry for her feelings. Emphasize that you value the relationship and are willing to solve problems that arise.
If there's a particular reason for the miscommunication, explain it moderately, but make sure you don't seem to be making excuses. Be transparent about your feelings and positions to give her more context.
Propose your own improvement plan so that she knows that she has recognized the problem and is willing to take positive steps to improve it. You can promise to listen more attentively and pay more attention to her.
Encourage her to share advice on how to improve communication. She may have some expectations or needs, and listening to her can help better meet her expectations.
Emphasize your care and importance for her in your reply and make her feel how important you are to the relationship. This can help alleviate the disappointment or sadness she may have felt because of her perfunctory performance.
Propose to increase positive interactions, whether it's face-to-face interactions, joint participation in activities, or other ways to show concern for her. Positive interactions help to deepen the relationship and make her feel more aware of your intentions.
Overall, responses need to be understanding, honest, and willing to improve. By establishing open lines of communication and working together to solve problems, it helps to maintain and strengthen relationships with each other.