People who like to reply to text messages at work

From your description, we can see that this girl is just very polite and doesn't want to cut off contact with you because she didn't reply to your message, which shows that this girl has a little feeling for you. At least you are the spare tire in this girl's heart. But if you say that this girl has a secret crush on you, it's a bit much, because no matter how busy a person is, he will have time to communicate with the person he likes. So if this girl doesn't communicate with you or is perfunctory, it means that this girl has no feelings for you at all.