So her suggestion is to only do the actual flying in SA, but do the ground exams, the R/T practical and the flight test in the UK. Very possible but you'd have to find a place in the UK on your own that's willing to go along with something like this - they're not going to make a lot of money off you.
You're forgetting one important thing...conversion. If you want to CONVERT the SA PPL to the JAA PPL then once you have over 100hrs the process is much easier I seem to recall. if you are in no rush to get a JAA PPL, just fly around on the SA PPL (quite legally) until you have reached the magic 100 hrs TT then convert.
Personally I'd go to the USA because you'd get an FAA certificate, it is valid in the US, N reg anywhere, UK in a G reg, France in a G reg for sure (they are the only ones I asked), it never expires and is easy to "maintain", there are numerous FAA certified docs in the UK who can do the medical, and you will find flight schools who are willing to rent to you. I did a JAA PPL in the USA, but had I known then what I know now, I'd have just done the FAA PPL.