You have brought to light yet another of the many problems with those online valuation sites. Their sources, the public records, show your home as a three bedroom, two and one-half bath. While the average selling price of homes in Bridle Creek over the past year is right around $157K, those homes did not include a finished, full basement.
Were these bedrooms added to an earthen basement (is any part of the exterior wall or floor of the basement below the surface of the earth)? If so, an appraiser wouldn't typically count those additional rooms in the total room count.
Was one of them added to a converted bonus/loft area above a garage? To be considered a bedroom, an appraiser most often would want to see a closet, standard window, a heat source inside, convenient access to a full bath nearby and a permit for the work with the county.
Of course, the public remarks would reference the finished terrace level or bonus/loft area rooms in the description so that potential buyers would know about them should you decide to put the property on the market.
The right real estate professional would be a much better source of information depending on your goals. For refinancing, an appraiser would be a good choice (most lenders hire their own). For selling, have an agent come by to see your home. Just want to know and keep up with local area sales? Get my automated notification tool at the link below and always know the price of a home that sells in your neighborhood. You won't get any telemarketing calls, spam email nor any other hassles, just a monthly report of neighborhood sales or changes in the estimate value of your home.
Hope that helps.