Sad story whoa! Expanding on Neb’s story ;-;
 
Her village got ransacked and destroyed by other ponies, she tried her best to save her little sister but failed. She did a good job of gearing up and then setting out to hunt down those creatures, and specifically this scene I can imagine her being in a storm, it’s hard to see, she’s upset and lost and confused, she hears a noise and brings out her knife with magic. She hears another noise and accidentally swings her knife and cuts her own face a bit. After that she just runs from fear.
 
I’d like to think she avoids other ponies that are trying to survive because she doesn’t want to fail at protecting anyone ever again