Thanks for your reply
Driver has been tested to see if she is using clutch correctly and examiner stated her driving techniques are very good
Car was bought from new in Jan 2011.
Getting a new clutch was big problem as it such a new car. Nissan eventually produced one and deducted £100 for all the hassle.
Mechanic believes the clutch is not suitable for size of car but chances of proving this is a manufacture fault very small as clutch burnt out and nissan will always blame driver and not their car.