Athlon II 245
ASUS M4N68T-M
Crucial 2x1GB DDR3 1333
Gigabyte HD 4550 <----This is going to be massive overkill, but $40 for a GPU is not bad at all, and $20 after MIR is a steal.
Seagate 7200.11 320GB
Cheapola Apex case
Antec Earthwatts 380w PSU (overkill lol)
Total cost: $334 including shipping -$20 MIR = $314
Good build for what she needs. I am assuming the OP is re-using the cd-rom in the old failed computer? Edit: Nevermind I see the post where he says he has the drive.