I'm no expert on the subject, but I've had my share of experience with single light setups.
I would stick to the strobe, and don't worry about the halogen for now. You don't want to mix light sources, but continuous lighting usually doesn't show up very much when you're using strobes anyway because the shutter speed is usually too high.
Do you have an umbrella or a softbox for your strobe? If so, you'll most likely want to use it to diffuse the shadows. Start by setting the strobe off to an angle, and pointing slightly downwards. Turn down/off the ambient lighting so you're using your modeling lights on the strobe and then on the opposite side put your reflector(s) and watch the lighting on your wife to see where it gets the brightest.
Reflectors don't have to cost a lot. I use foam core board (yellow on one side, white on the other) and those big foil car window reflectors. Recently I started playing with using an actual umbrella as a reflector and that seems to work well.
I'd say that at 125 W/S you'd probably want to leave it at full power. You MIGHT need to turn it down just a hair. Obviously you'd need to play with it. Light meters come in really handy here. Depending on your camera, I'd set shutter speed to whatever your sync speed is (depending on camera it's likely 80, 125, 250 or 500). 125 is usually always safe unless you have a Rebel which I believe is 80. If you're shooting film, take at least 3 consecutive shots, start with an aperture of 8, then 11, then 16. If you're shooting digital, watch the histogram in your review mode and make sure you don't have anything touching the right hand side.
I like the background in your pic, it really adds to the pic, and your wife looks natural in front of the camera. Play around with your lighting and post your results back here. I'll be watching for your entry on the site! [img]/ubbthreads/images/graemlins/wink.gif[/img]