Nancy-
Welcome!
Your weight isn't that far off of some of the folks who post here (myself included), and except for a few really light racing bikes, I seriously doubt it would be an issue. Be honest with your shop - and they may beef up your wheels a little (i.e. give them extra attention to make sure they are true, etc). Otherwise, not an issue
There are LOTS of bikes that would work great for you. Is your tour supported (i.e. someone else carries your stuff) or self-supported (you carry all your stuff)? That will make a difference in the kind of bike you'll want to get.
I have a Trek 520, a Bike Friday and a Surly Cross Check - any one of these would work for either kind of tour (though the Friday and the Trek will handle fully loaded touring better). Lots of folks like the Jamis aurora (another touring bike). There is also the Novara Randonee. If these bikes are out of budget, you may want to try looking on Craigslist or otherwise at 2nd hand bikes. I bought my cross check off ebay.
Let us know more, and we'll try to help
CA