I would not touch a Mini sold between 2002 and 2004/5, Cooper or Cooper S.
These originals had many issues, and specifically the Cooper had a Midland gearbox that was crap. The facelift got a better box from Getrag.
Other issues on these were:
> Power steering failure.
> Steering rack issues.
> Electric window failure.
> Dashboard rattle/s - Fix is to strip dashboard and fit a better bracket = $$$
Engine was based on a Chrysler Neon, but not identical. Not very efficient or economical, but I did not ever have or hear of engine problems.
Also, to change the clutch on the mini is an engine out affair...not cheap for a stukkie on a toight budget.
If she must have one, rather get a facelift, non supercharged one.