extension for tier 4------

[razi1234]

hi,
I hv a scenario here ,plz respond,
my friend came in uk on april 2007(her student visa was from January 2007 to September 2011,acca course that time)but in these 4 years ,she did not studyand then in September 2011 she sent her application for tier 4 student for level 5 ,she got visa till march 2014....now she her level 5 has been finished ,can u plz tell what possible ways she has to complete her 10 years ,,,
1-can she simply get cas letter for level 6?
2-is she fall any type of cap put by ukba?
3-how many years she can spent on student visa more?
plz respond ,thanks