Another vote for Sam Adams Cherry Wheat. I truly love this beer. I seem to remember also trying their cranberry lambic, and liking that, but it's also harder to find.
I'd also highly recommend the New Glarus Wisconsin Belgian Red
. While rather expensive (and distributed in a wine-like bottle), it's quite awesome, and makes a great "special occasion" treat.
Has she tried the various wheat beers? In particular, the German hefeweizen seems sweet to me, but the cloudiness of the unfiltered yeast turns some people off.