If its just for general usage such as email, internet, perhaps schoolwork/uni assignments then 2GB should still be enough but ideally 4GB has become a comfortable norm these days (providing her model of laptop can take that much RAM of course).
Here's a rundown of how much RAM a laptop should contain based on various usage patterns:
http://www.laptopmemo...puter-memory-you-need
111GB on C:\ drive suggests she has a 120GB hard drive that once formated yields 111GB of free space.