Not sure where you're getting that info from?
Not knocking you if you want to go Intel fair enough, but the i3 does not blow the X4 out the water
comparison
Note that some of the comparisons are lower is better, overall theyre not too dissimilar in terms of performance, however as you state she wont upgrade the cpu, than for future use, a proper quad core is more likely to be better than a dual with HT as more and more games/apps get coded to use the extra cores, its upto you obviously just wanting to make sure youre as informed as possible
Edit: It may also be worth noting that for watching movies etc the Intel is slightly better as it has better sound, however for gaming, even light casual gaming, the AMD set up has better integrated gfx