Hello, I wish your friend well, start by looking here :-
http://www.ukba.homeoffice.gov.uk/
There should not be any problems, if she has not broken any conditions of stay in the UK under her working visa and she has not overstayed in the UK for any length of time. There will be lots of useful information on this site. Sorry I cannot give you any accurate information at the moment as I am busy putting together my wifes ILR application ready for this monday.
Good Luck, if I find anything on here I will post the thread you need.
Paul & Anilyn
