"Ashly" did not receive a response for two days and became agitated at the lack of communication. Yes, they could have settled this upon meeting face-to-face, but she has a case to be frustrated and probably has less patience for her prospective roommates as a result.
"Guistinna" is overly defensive about her refusal to use email and is responding to a message that was spawned out of anger. Of course it's abrasive, so her shock at the harsh language is silly. She should have been more timely with her response, even if her roommate's demands are excessive.
"Ashly"'s anxiety is normal, although she probably should not have expressed her feelings so openly and in such a crass manner as she did in her response.
They're both immature. There's nothing shocking about this. Kids are stupid, insecure, and defensive. If either side were any more mature, it would have been handled better. "Guistinna" needed to apologize for her tardiness, especially considering that they had all communicated before about methods of correspondence. Apparently, they chose email because email addresses were swapped. A simple message to say "I'm sorry I can't respond in detail right now, but I'll get back to you as soon as possible" would have prevented this entire miscommunication from occurring; her neglect was interpreted as a gesture of disrespect. It is NOT difficult to send a quick email, especially if one has enough time to browse Facebook and use "group chat." Two days of waiting and aggravation gave "Ashly" a sense of entitlement to the bed and closet of her choice, as it seemed to her that neither of the other two roommates cared enough to respond.
Guistinna and Winnie come across as irresponsible with regards to communication -- they are the kind of classmates who wouldn't respond in a timely manner to group project inquiries and leave the entire operation in disarray and confusion. Pouting on social media about an incident that they were at fault for is also petty.