Deb--
Are the wheels on the MTB you're riding 26" wheels or are they smaller? If they're 26" you might want to get a smoother set of tires to use while you're waiting on your new bike. Losing those knobs will help your speed.

I'm not sure what area you're in, but it might be worth your time to check on some bike shops farther from home. Call first to see what they have in your size so you don't waste a trip. My mother-in-law went as far as Wisconsin (from St. Louis, MO) to test ride recumbents when she was in the market.