For the "surprise" you could always blindfold her and drive her down to the camera store.
Here's an example of why I think it's important for a user to handle a camera first: when the Canon Rebel XT came out, it was a LOT smaller body than its predecessor, or any of Canon's other bodies for that matter. There's almost nothing to hang on to to the left side of the lens mount on them. People with larger hands, like myself, found them particularly awkward to hold, especially with larger, heavier lenses where a solid grip on the camera body was essential.
Now I don't know what the body specifics are of the Olympus, or the D60, or anything else you've looked at... but if she ends up with a camera that's uncomfortable for her to hold, or that the menus and controls are confusing or awkward for her to reach, then the camera won't be as enjoyable to use, and stands a greater chance of being left sitting at home collecting dust.
Of course, you could make sure to hold on to the receipt so she can exchange it if there are any such issues... or how's this for an idea: arrange with the camera store to have the two or three models/packages you're considering, set out together on display, with big red bows on them... tell her you're taking her to dinner or something, and you just need to stop in the store to pick up some film or something... drag her inside with you, where she's then presented with the cameras you've chosen, and she can choose the model/package/system that she prefers.
As for "wouldn't let you buy it for her"... tell her you already bought all of them and you're just getting a refund on the ones she doesn't want
Or tell her the others are gifts for family and she gets first pick. Or whatever.