Chey--
It's very safe in Alexandria--I just came back from a short trip there--I am a lady in her 60s who was traveling by myself and felt just fine. I stayed at the Hilton Garden Inn up the hill, which is very new and nice, but many people stayed at the Embassy Suites for the Gathering last year and liked it.
If you want something to eat without paying DC prices, there is a restaurant up the hill called Table Talk (I think--Table something), which serves a fantastic full breakfast at not much more than diner prices. Also, right next to the Embassy Suites is a sports bar restaurant, but you don't have to sit inside with the TVs--they have a very nice covered patio that looks toward the Metro, so you can see the Metros come and go as you eat.
Probably the most dangerous thing in Alexandria is the uneven historic bricks--just watch where you're walking and you should be fine.
Hope these suggestions help (and are not too late) and that you have a great trip!