The girl sent me a message asking if I had eaten it, and I didn't know what it meant.

First: If it is a careless girl, she may just send her hand by mistake. Second: If she is a girl who is not very expressive, she may want to say that she is waiting for your reply. Third: if you are a girl like a man and a woman, you may be asked if you have eaten. Have you slept? What are you doing? Wait a series of questions, just to save trouble. Fourth: If you are a girl with ideas or a girl who has a crush on you. I want to see what your reaction is. If you tell her something other than dinner, she may know everything she wants to know and she will be ecstatic.