If you don't make a big deal of it, neither will the kids. Do you have photos of the wedding. Going through the picture box together is a great way to introduce kids to family history. It gives you a chance to mention tidbits of history as the photos pass through hands. If they want to know more, they will ask. Its kind of like those talks about sex or adoption, etc. Don't give more info than they need. Depending on their age & the curiosity factor, they will prompt you for more info if they are ready for it.