That HDD is a waist of money, you can get so many more GIGs for So little. And a little more then Over kill on that case for a budget system? you think?.... since you say she's probably only using it for Internet/word, you could probably find a motherboard with one of those Built in Onboard Nvidia 6100 IGP chipsets... might beable to save you some on the vid card. check how much it might be at newegg though.... and since its such a small system i guess you can buy any 350 watt or maybe less PSU that you wont.
250gig Seagate SATA = $85
ATX Case = $14 + Whatever shipping may cost you
EDIT: wasnt looking at the board for a while, noticed someone already linked you to a 6100 IGP MoBo.
EDIT again: i just noticed your own specs... i guess if you desided to you could, get this 250GIG Seagate for yourself, and pass your 80GiG on to your mathers comp.