First -- pace yourself. You alone know your body, if it signals potential damage - slow yourself!
Avoid white starches and choose whole grains.
Drink a lot of water -- lemon water is effective at flushing toxins, which retain fluids.
Take your baby for strolls in the cool of the morning or day -- or go "mall walking".
Be sure not to be hard on yourself. Setting achievable goals can be healthy and often prove helpful -- while setting tough goals often are discouraging when you don't lose 2 pounds a week. A weekly loss of half a pound to a pound after your initial "water weight" is lost is attainable and achievable without too much stress on your body or schedule.
Keep us posted on your venture!