The ISO range figures are wrong on that chart for the 500D, it has the same range as the 550D ie 100-6400 + H (12800), 1600 is very usable, 3200 usable at a push, the other two only if you like really grainy images.
IQ is apparently better on the 550D as is noise control.
That done I would rather have the better noise control at high ISO of the 500D than a 40D.
The 500D is a no brainer at the moment, just so many good prices and deals.
I ditched the idea of the kit lens and went for the 50mm 1.8, if shes mainly going to shoot people etc then I would recommend doing the same then add something like a fast 28-70mm later