I wasn't a fan of exercise until i found out that i was actually working out to intensely and feeling uncomfortable.
Walking regularly is a good start & getting hubby involved is great idea, since it should be more enjoyable and your far more likely to continue doing it if there is some external motivator.
It is however important to raise your heart rate for the correct duration when you exercise to gain optimum fat loss & the additional life time benefits as i mentioned here. viewtopic.php?f=3&t=14317#p129800
So i guess... as long as you keep your heart rate in the right zone. Yes!
If you go to high you get into the anaerobic range and the benefits for fat loss are actually diminished - it becomes more of an endurance benefit.
if its to low.. its great your doing something but the benefit is not really there.
Over time you'll get probably bored with just walking.. and want to spruce it up a little with some different activities or adding some intervals of higher intensity (a short run then walk).
But for now.. just keep at it and enjoy the routine of doing it.