WP holder returns, Can dependant continue till visa expires

I am in UK on a work permit with my wife as my dependant.

My work permit and visa is valid for another 1+ year (so my wife's)

But I am planning to go back to my own country immediately to explore better opportunities

My wife, on the dependant visa, is currently pursuing a post graduation from a England university. She would like to stay here till he finishes the course (course finishes in another 6 months)

a) Will she be able to continue here on her resident permit even though I leave the country?

b) Will her resident permit get cancelled (as she is on dependant visa) , as soon as I leave the country. In that case does she has to go back and apply for a student visa and come back?

c) Or do I have to stay here until she finishes her course?

Please guide