I am unsure what you mean by "I reseted my whole Mac..." Do you mean she erased the hard drive and reinstalled the operating system? of did a PRAM reset? SMC reset? something else?
Is the able to boot the machine but not able to login to her account? Or are you unable to completely boot?
Let us know, we will keep working with you.
Best of luck.
If we are going to help you fix her MB, you are going to have to give us specific facts about it.
Is it running 10.8.1 as is stated in your profile?
What is the size of the disk?
How much free space is left on the disk?
If you want a guessfrom your story it sounds like the free space has been run low enough that the system directory is corrupt and the system is starting to lose bits and pieces on itself. If this problem is not resolved and soon the corruption will only get worst until the MB is no longer able to boot.
The issue the MacBook Pro OS X has a startup message with "your startup disk is full, you need to make space available on startup disk by deleting files"
Ok so now the from here the screen is just blank and I don't know how to proceed... I cannot even get to the log in page to sign in as a user... Any help is appreciated