This used to happen to our family too especially when kids were small. One person's cold would cycle through the whole family several times so there were several months during the winter when at least one person in the family was sick and boy was that a miserable time. Now a few years later after better educating ourselves (mercola com, greenmedinfo com) and seeing nathropathic/anti-aging drs (most don's accept ins. but its well worth it to improve your health) we hardly ever get sick. We did the following"
What you need to do is live a healthy life style, exercise no junk food as Sugar (and high fructose Sugar is in nearly everything) stresses and weakens your immune system. Excessive carb intake (breads, crackers, pasta, rice) is broken down to sugar. Destress by doing Chi Gong/Tai Chi.
Unless you live in the tropics and spend a considerable amount of time outside you need to aggressively supplement with Vit D and C. Your body uses much more of them when your sick so start taking more than usual before you get sick to head off the worst of a cold and to get better faster.
Also as part of a physical make sure to get your Vit D levels and thyroid checked (esp. for women) Vit D for optimal immune function needs to be between 70-90, mine used to be 20! The RDA of 400 IU/ a day is just way to low.
I know some of this sounds like a lot of work but isn't your good health worth the effort?