<human>: Give me the gist of the text in a nutshell

I met a girl about two weeks ago, and there definitely seems to be some chemistry.  However, she is extremely direct to the point of being rude and callous.

For example, I have a Marvel poster on my wall and every time she's over she remarks (with not a drip of humor) "God, I hate that poster."  When I texted her today to comment on how there were some crazy rainstorms near me, she replied "No shit."  When I offered to bring her something from Starbucks on her break from class, she declined, and texted "Thanks, you're the best!", then adding "That was sarcasm."

I'm all for not sugar-coating things, but I'm generally a positive, polite person, so her approach to things is throwing me off.  I'm not the pushover type, but I'm also willing to put some effort into a relationship, especially in the beginning, to see if it works.  Do you think her blunt attitude is a red flag or is her directness a normal personality trait (that I have to decide whether I can coexist with).
<bot>: She apologized for being a bitch, said it was because she was stressed out.  I told her I couldn't date someone who would treat someone harshly whenever they were having a bad day.