What should i tell my friend? I dont know if shes mad at me?

ok so my friend Kathryn was invited to one of my other friends, Brianna, house on new years eve. she told me she didnt want to go because she didnt know anyone. I was invited too but i couldnt go. I told brianna that kathryn couldnt go to the party because she didnt know anyoen there. later kathryn called me and was a little annoyed at me for telling brianna that she couldnt go because she didnt know anyone. I asked kathryn later on if she was mad at me but she said she wasnt and she didnt seem mad. then today i was texting to her on the phone and kathryn told me she was going ice skating on saturday. i didnt know what to say so i asked her if these two girls that we hate were going skating too. kathryn told me that she were going ice skating today. I didnt get what she said so i asked again about the two girls and i said "are the two girls going skating on saturday" Then she texted back "NO I AM GOING ON SATURDAY" Then i was like sorry i didnt get what you said the first time. then she was like whatever bye. So now idk if shes mad at me, i want to talk to her again but i dont want to just be like hi are you mad at me? so how would i start a conversation to get to the point that i want to ask her if shes mad at me for anything???