So what she's looking at is a Powerbook vs... what?
As far as the networking aspect (esp wireless,) that is a point in the
Apple's direction. I'm dealing with a wireless network here, and my XP
machine will occasionally decide it doesn't want to use the connection, but
pick one from across the street or somewhere - which I've told it
specifically not to use.
Heavily into digital photography - the major software programs run on both
Mac and Windows. iPhoto's nice, but it sounds like she'd outstrip it.
My suggestion, take her to an Apple store (or independant Apple retailer)
nearby, and take her to Best Buy or wherever. See which ones (a) look better
to her (not aesthetics, but the screen,) and (b) feel better. Yes, you can
use a third party keyboard and mouse, yes addons are simple plug-in-and-go
affairs, but you have to be happy with the base unit.
Also... when you do go, don't help. Let her see how fast she figures out how
to do things on the PC and on the Mac. Whatever she's most comfortable with
is what she should get.