DONT DO IT!
Goggles are a horrible gift to give unless you know they already fit her face/helmet. So unless you have been with her to try them on, it's a pretty bad idea.
I can't wear smith IOs, Stockholms, Crowbars, Anthems, Prodigies or most of the other common mens/womens goggles.
I can wear Rogues, DSX's, and Aframes. That's about it. Sure you picked out the DSX, I like the goggle. It fits me well, but it may not fit her at all. The most versatile goggle I have seen has been the Aframe, but even still, I know girls that really don't care for the look.
So in all seriousness, I wouldn't.
If you are looking to get her something in that price range, pick her up a cozy marino wool thermal. Most girls don't have those and after wearing it once she will want to wear it every day. Or buy her a gift card for the price range of goggle and write in the card that you wanted to buy her goggles, but you need to bring her in to make sure they fit. If anything, that will make you sound more knowledgeable.