Okay, I am a girl so it will be easy to explain.
If a girl is upset at you through text then here is 10 signs to help you:
1. She puts more than one dot next to her texts.
2. She says 'Whatever' when you say something nice to her.
3. She says 'okay' when you ask a question on where to go and you pick it.
4. She doesn't text back within two days.
5. She sends you a gif or a picture of something to change the subject.
6. She decides to text 'What are you doing' as her first text, her thinking that you done something wrong. aka, she doesn't trust you.
7. She tried to change the subject by asking a qiestion or just doesn't answer you and sends a picture of a random thing in her room.
8. She does all caps when you ask her something sensitive.
9. She puts '....' as her answer when you hit one of her nerves.
10. She deletes and blocks you off anything you and her have contact with.
I hope this helps you, mate. I hope you and your girl friend have a better relationship! :)