That's great! At that age my son started playing computer games that developed his mouse, reading and typing skills. IIRC one of his faves back then was Zoo Tycoon. He loved letting the lions out of their pen... Today he loves all kind of stuff, but he's hooked lately on doing his Lego Mindstorms and playing Nethack.
I think one nice product that might be helpful for the very young is keyboard stickers. You can get them in lower case, color-coded to learn typing, in alternate character sets, etc. My son found his keyboard much easier to use with lower-case letters, when he started. Now, at five, he is in the beginnings of touch typing with no teaching. He somehow naturally adopted the right hand position and everything; I don't know if it's from watching us.
Another thing that might encourage her is to have a right-sized mouse. There are lots of options for little hands, due to mini-mouses made for laptops, plus options inteded just for kids. If you live near a Staples or similar store, you can probably try them before you buy.
If she's online, make sure you have net-nanny software installed, even if you think you're always watching and could prevent a mishap. (Sorry; it is probably already on your radar.)
