You're right, even normal person would be like her. People are too caught up in the "this is a manhwa, she shouldn't be like this!". But author want to portray how normally people would react not how a manmade character would react. With just this you can see the difference between isekai manhwa and isekai manga are.
She is being weak. For now. Its nothing people should hate for. Being strong doesnt mean I'm strong 24/7. So what if she's weak right now. WHAT WHY ARE THESE GUYS DISSING HER FOR BEING WEAK. I WAS WEAK FIRST BEFORE I AM STRONG OKAY. WHAT THE FUCK LIKE WERE YOU ABLE TO WALK 3 SECONDS AFTER YOU WERE BORN HUH HUH HUH HUUUUUHHH GAAAHHH IM MADE DAMNIT
like people are saying she's weak?? um okay try to stay calm when someone literally gets shot in front of you trying to save you. she feels guilty that she has burdened another person and that would be hella fucking traumatizing