Photoshop uses OpenGL not CUDA so as long as your card is certified for OpenGL you should be fine. Onboard graphics should be sufficient for simple, 2D photo editing, but if your mother uses any of the 3D features in Photoshop, she'll likely need a stronger, dedicated graphics solution.
Both of the builds posted on here should give you some insight into what you need. A fast quad-core will do the job great. I can't remember where but I've read somewhere that Photoshop utilises more than 2 cores, but I'm not sure there's much benefit going for six over four. You can either go the AMD route and grab the Phenom II X4 Dadiggle pointed to or go Intel and the 2500k that JackNaylorPE mentioned.
The only issue with Dadiggles build is that all of that RAM won't fit in the motherboard. He listed 6 x 2GB sticks, but the motherboard only has 4 DIMM slots, so you'll either need a different board or different RAM. How much RAM you'll need depends on the kind of work your mother will be doing. As Dadiggle mentioned, if time is money then the more the merrier but if it's more of a hobby than a profession and she's not working with particularly large files then she may not even need a full 12GB. I run Photoshop as a hobby and so some basic photo editing and I haven't had any hiccups on 4GB. That being said, I don't work on really large files and don't use a ton of filters or effects so take that with a pinch of salt.
EDIT: Scrap the below, just remembered SandyBridge also has dual channel memory, I was thinking of the 1366 for some reason! The same applies as to the AMD build though, sorry for the confusion.
[One thing I would say is that keep in mind that the i5 2500k uses a triple channel controller whereas the Phenom uses dual channel. So depending which route you go down you'll want to buy your memory in sets of three or sets of two or multiples of each etc.]
^Both CPUs utilise dual channel memory.
If it were me, if I'd grab 2 x 4GB sticks. If you feel that 8GB isn't enough if you go AMD you can always had more later. As others have mentioned though it all depends what kind of Photoshop work your mother's likely to be doing. Good luck!
If you aren't doing anything video intensive... it might be good enough. Could always add in the discrete card there too... but you would have had to invest in a H67 board instead of a more performance oriented P67. Don't know if the Quick Sync would figure either... (a plus for H67)
Facebook
Twitter
Instagram