My uncle gave me away when I got married. In the car on the way to the church, he also asked if I was quite sure that this was what I wanted. I wasn't sure then, but felt it was too late to call things off, when everyone had gone to so much trouble and expense. So if you are going to ask that question, don't leave it too late. I probably would have backed out if it had it been two weeks or so earlier, or at least postponed it until I was sure. Instead of that, my fate was to give birth to two babies in two years, then my husband decided it wasn't for him, kids and marriage and left us penny less and went back to his parents house and never gave us another thought and certainly contributed nothing to bring the children up. So please give her the chance to back out before the day. She might well thank you in the end.