I have the Tom Tom 930 which I find is great. I bought that over the 730 because the 930 came preloaded with Europe maps and by the time you bought the 730 and the maps the cost difference was neither here nor there.
Having said all of that I am concerned about it being stolen and if your mum is going to be using it all of the time I would be more inclined to buy something like this.
http://reviews.cnet.com/car-gps-navi...-32815608.html
The story I got told was people have started going to football matches are walking around the car park till they see the tell tale mark on the windscreen from your gps. Smash and grab. Fire it up and hit home. They know that you wont be home for at least 3 hours.
Brendon