The eBay ad says you can use it wireless, so it's clearly equipped for it. But you would need to have an account set up (or however it works in the US - we're a bit backward in Australia). You probably need an Airport or similar - husband is brilliant at this but he's currently on his way home from work, I'll ask him when he gets in.
It looks to me like you've got a really good laptop with some great software already installed. There will be small tweaks she may want to do, to set it up how SHE wants it. I think the G4 laptops also have the track pad - husband has mine set to active, so I sometimes accidentally move the cursor without realising. But otherwise, it's how I like it. easy child 2/difficult child 2 doesn't like it that way, she has hers set differently. She bought it herself with money from her 21st birthday.
Do you have an Apple Service Center anywhere within phone range? If they baulk at helping you over the phone, point out that now you are Apple owners, you will be in the market for other peripherals and it will be good to be in touch and getting help from a Center close enough to visit to buy stuff. The Centres in our area are really helpful, although sometimes they don't know enough. But when it comes to starting up - they have no problems.
We are still on cable at home, because we're out of range for wireless. So we have a spare cable running off our ADSL router, husband or easy child 2/difficult child 2 use the cable to hook in and go online. Although we have the internal modems in our Apple laptops, we need the router to access broadband. We can still go on dial-up with any of our laptops, we just unplug the lead from the phone and plug it into the modem port on the laptop. If you do this, you will need to program the phone number into the new computer - it will probably still be set for the contact details of the bloke who sold it to you, unless he removed it.
Any configuration you may need, will be things like your password codes etc specific to your account. But if you cable to the router (as we do) then she should be able to hook on, no problem.
The thing with Apple, they are sold as a package ready to go, a kid can set them up and go online in minutes, with a new computer. The G4 laptop is very capable. It's a good buy.
We're an Apple household, we've even managed to stay Microsoft-free. We have a compartment for Microsoft, we can translate any file, we're virus-free. VERY occasionally, a virus comes out that affects Apple. We saw one about ten years ago.
I recommend you just hand the thing over and watch her squeal with delight. She will work it out for herself.
Any problems, I'll get husband on to have a look for you. He'll be home in another hour.
Marg