[MysticCat]

Well, I'm crashing too, but here's my $0.02:

I'd probably be inclined to use her unmarried initials, especially if you are giving it to her before you're married. That's the name she was initiated under, those are her initials when the gift is given, and that's still who she will be, even if she takes your name legally. To me, it just seems a little more traditional for some reason. (Perhaps it's because in the part of the cemetery where my family is buried, you see three or four generations of women whose stones use their full maiden names, followed by "wife of . . . .")

One alternative: hold off on the engraving until after Christmas and ask her which she would prefer.