I agree with Marianne0558, if this is her first time as well as yours it will most likely hurt. Also, since you have never had sex, you may be a little clumsy initially, which may add to the discomfort, but I believe once you get started, things will happen naturally.
Now, she should lubricate if she is arosed, so please don't forget to spend some time getting her as excited about your bonding together as your are by showing her affection, tenderness and using a loving touch. If she does not lubricate, which can happen if she is nervous, and traditional wedding nights can be that way, then lubrication can really help.
Good Luck, all the best,
Wendy