So I know that you guys are blowing up because Anna and Elsa aren't themselves, and I can explain. So, Elsa thought she was hearing things and didn't bother to knock because she was expecting her sister to be in the throne room.
Anna was upset at Elsa because she thought that after the coronation, Elsa would let her in.
I hope this was a good explanation, and thank you for your lovely reviews! On to the story...

Can I say something even crazier? Ch 3
Anna sat on her bed, wondering why Elsa wouldn't let her in. " There must be a good explanation. She was clearly lying about getting dressed, so she was most likely waking up. Either way, she should've let me in! I'm her sister! Maybe I should've gotten engaged to Hans. Maybe I should've run away. Nobody would care really. Well, the kingdom would. Elsa might. I wouldn't go anywhere though. If I did flee, I'd have to steal a boat! Or go to the North mountain. Hmm..." Anna snapped out of her thoughts when there was a loud knock on her door. " Anna? " Dammit. Elsa. " Uh, I'm busy reading! Come back later! " Elsa shook her head. " A young man named Kristoff accused a shop owner today. " Elsa gave a weak laugh. Anna buried her head under her pillow. " I'll see you at dinner? " Anna sat up, which caused her pillow to fall off her bed. " Uh, yeah. Of course Elsa. " Elsa smiled. When Anna could no longer hear footsteps she picked up the pillow and lay on top of it. " I'm in for a hell of a ride. " She muttered.

Sorry for the short chapter guys! I'm really busy so I didn't really have time to write this! See ya next time :3
~HGDisneyGeek