An Idea To Get You Started
It would be good to know approximately how old you and your sister are, but if the 76 in your e-mail address indicates your birthyear, I'll give you a good plan if you're in your mid to late 20's.
Given that you only have a week, I'd head northeast rather than out west. Tennessee is a great option if you haven't seen much of it. Memphis and Nashville are excellent cities for nightlife and (coastal folk don't chuckle) southern culture. Great Smoky Mountains National Park is supposed to be amazing in the early Spring before the very large crowds arrive.
If you leave early enough the first day and don't get delayed, you can be eating dinner and listening to great live music on Beale Street in Memphis your first night. From there, and from what I can remember, Nashville is about a 3.5 hour drive from Memphis...easily knocked out in a quick morning or evening driving shift. When you're there, say hello to the "sloshed" horse in the Wildhorse Saloon.
I'm not exactly sure (and too lazy to Mapquest it), but I can't imagine that the Great Smoky Mountains are more than a 4 or 5 hour drive from Nashville. If you get a nice run of warmer weather, you'll want to spend at least a day or two exploring the park.
You're looking at a pretty long drive home from there, but probably not quite a thousand miles. One long day of driving and part of another is all it would take.
If you give yourself a week, you'll have plenty of time.
Good luck and safe driving.
AB
I don't have anything to add....
just impressed that you unearthed my old screen name. When the board was updated a few years ago I completely forgot my login password and "Laura" went the way of the dodo.
Laura