More thoughts on Southwest...

- For many of the routes you are talking about, their frequency to/from Dallas is the best. That's a big advantage to a business traveller - if a meeting ends early, she may find a flight that gets her home an hour earlier, instead of having to wait. But note that Southwest requires full-fare to stand by, though, so make sure her company will ok full fare tickets or the cost differential if she needs to stand by.

- Southwest offers a "companion pass" if she gets 100 credits in a 12 month period. This pass offers unlimited 2 for 1 travel for the year after it is earned. If the two of you will be vacationing a lot (if she's not burned out), that could be a huge benefit.

- On other airlines, once she has elite status, she will be able to upgrade some or all of her flights to first class. Southwest has no first class. On her short intra-TX hops, that's not too big a deal, but when she's heading to either coast, it's a lot nicer to be up front.

- Don't forget the Wright ammendment. Southwest will not let her but a ticket DAL-LAX. To get beyond TX and the adjoining states, she'd need to buy two separate tickets. This does mean twice as many credits, and may still be as cheap as a single ticket on AA, but it can be a hassle, and may look odd on an expense report, especially if costs are re-billed to clients.

- I think I've heard that the Wright ammendment only applies to purchased tickets, that is, you can redeem an award connecting thru to California, etc. Ask in the Southwest forum for more info. But they still only fly the lower 48, so if you're wanting to use her awards to get to europe, carribean, hawaii, etc, then look for another airline.

AA is probably the best bet for you, but consider what your leisure travel plans may be. if it's frequent, short trips, SW may be worth considering.