:-)
Shame about her HP, but I'm sure she'll love the PowerBook. My wife's Titanium G4 PowerBook (667 MHz) has been a trooper. The only problem it has is that one of the hinges froze and she ended up breaking it trying to force the lid open. The other hinge is fine. I don't know if Apple's changed the design any, but if not, a drop of sewing machine oil or similar on the hinge axles might be a good idea.
I'm sorry I can't help much with the disinfecting. There are Linux CDs that include Win virus scanning (Knoppix does, I think), but I don't know how up to date they are, etc.
Virtual PC is very good (recall it was developed by a company that MS bought). I don't use it myself, but people at work swear by it. It's a little pokey, but lots of RAM will help.
I don't know how well it would isolate virus infections. She probably shouldn't use Win programs to use the Internet while on the PB.
But WiFi -g is er, WiFi -g -- right?
Well, yes and no. There are differences in the ease in setup and how well they work, just as all 'scopes aren't the same even if they have similar bandwidths. Recall my adventures with [link|http://z.iwethey.org/forums/render/content/show?contentid=195611|802.11g]. The Buffalo box I have works well. The Netgear I had previously, didn't. Note that the Buffalo has an AOSS mode that only works with other Buffalo parts. I think the other big vendors have something similar but probably incompatible - it's a higher throughput and/or longer range and/or more secure mode. I don't use AOSS.
Our home network is 802.11g once it enters the house (with 10/100 baseT Ethernet switches where the PCs congregate). My T41 laptop (802.11g) and our G4 TiBook (802.11b) both work fine with it.
I haven't run "Shields Up!" on this network recently, but I'm not concerned. The Buffalo WAP/switch blocks almost every port by default. Hardware firewalls are very handy to have and inexpensive.
Her G4 should be able to find and work with almost any standard 802.11b or 802.11g Wireless Access Point (WAP). If she bought an Airport Extreme Base Station (as I read your post, she did), and she has a working Linksys that she's happy with, then she could take the APEBS back. But she should make sure the G4 works with the Linksys first. Her Linksys and/or the APEBS should have ways to block ports too, IIRC.
Most of the smart networking hardware these days is configured by a browser. My Buffalo is at [link|http://192.168.0.1|http://192.168.0.1] The Linksys should be similar - check their web page for a copy of the manual pamphlet which explains how to configure it and so forth.
What are the odds on frequent Beastware reloads, for the usual reasons - when emulated?
As long as she doesn't get infected again, the "if it ain't broke, don't fix it" truism applies. As long as her apps don't need an updated OS, she shouldn't need to apply OS fixes. But she'll have to be vigilant, especially if she works with PC files from others. And she'll have to remember not to do network stuff with Virtual PC.
HTH a bit. Luck!
Cheers,
Scott.