The only thing 'missing' is an optical drive, which I'm sure you won't overlook when putting it together. And probably install XP instead of Vista (sure way to improve performance!)
Depends on what she's going to do on it really.
My spec is quite a bit lower & I do the normal things, including play many older games like FEAR & Far Cry....
• Athlon XP 2800+ CPU (32-bit, single core)
• Gigabyte nForce2 motherboard
• 1.5Gb PC3200 400Mhz DDR RAM
• X800XT Platinum 256Mb GPU
• 2x 80Gb HDDs (non-RAID)
• 1x DVD-rw, 1x combo drive
• 550w PSU
• WinXP Pro (or Linux - dualboot)
If she doesn't do any high-end stuff or play games, can we do a swap ;-) - I'm also willing to pay for the difference! G