Eeek that's tough. If it were my boss I'd ask her about using it as personal time because I know her and she knows about the wedding (she came with her husband!) and I know she'd be okay with it.
Butttt if you think they might not be okay with it, I wouldn't ask because then when you do it anyway it'd be real obvious!
Sorry this wasn't the best answer, but I guess it just depends on your boss/company policy.