get a monitor!
if she is not going to overclock than a B75 board is just dandy. a 550 watt PSU will be enough for any graphics card set up out there. i was tempted in squeezing an SSD in the build but getting a monitor eat that up . . . so here is/are my suggestion(s)
a little over budget with upfront costs: PCPartPicker part list / Price breakdown by merchant / Benchmarks