Good Day vocalcoach
You may have more opportunities for walking than you know. Do you tend to drive to the store, which is just down the block and around the corner for a quart or milk or something? Walk instead! The ozone layer will thank you for it.
When you have business of some kind in an office building, are you taking the elevator for only one or two floors up? Take the stairs.
When you drive to the mall (and say its the middle of the day, so there so be plenty of parking open at that time) do you strain to park as close to the door as possible? Park as far away as possible and take that opportunity to walk!
If you can get some light ankle and wrist weights (and possibly even a weighted belt?) that you might wear throughout the day. I would imagine this would be good for muscle toning, which is very important, especially for women!! My understanding is that weight training is crucial for women because it all has to do with the thickening and hardening of the bones.... the whole calcium thing.... crucial.
The muscle toning will enable your cardiovascular training, I think. What I'm saying is, if you start by carving out little opportunities to walk here and there, you might eventually find you walking to driving ratio going up without your even thinking about it.