Let me also give Joe Rocket gear a plug.
I use Joe Rocket gear and my girl went thru the Joe Rocket catalog and picked out stuff she liked. I also grabbed a set of gear for her that matched mine. She liked the matching gear for us when we ride together, and she has her own seperate gear for when she putts around town on her scooter.
You can get J.R. gear to match just about any bike. All the jackets have removeable warmth liners, have dual density removable armor and have a ton of pockets and also warm weather cooling vents.
Dude, that's your girl, protect her right. Get her a full face helmet, riding jacket and gloves. Make sure she wears jeans when you ride and closed toed shoes, preferrably high on the heal high tops or boots. Protect that pretty skin of hers. [

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You can get a great deal on HJC or KBC helmets on eBay, both in solids and patterns. I tend to like the HJC's a little better than the HJC.
I really prefer Shoei's and Aria's and you can get them on eBay too, but those can get pricey.
Good luck.
-Flash
"We are what we repeatedly do. Excellence, then, is not an act, but habit" -
Aristotle