I agree with aguiedranch,your mare is very nice,but there isnt anything wrong with the other mare for what you want her for,and pretty doesnt make a good riding horse.The way I look at is if you think you are losing money how much is a broken leg or broken neck or broken child going to cost you? the big time working cow horses are not the huge tank people think all QH should be,most are running 14-14.2 and built very much like the roan mare,around here the roan would sell for more then yours,green mares arent bringing anything no matter how pretty or how well bred,you could always try the mare for a day ride,like 5-10 miles and see if you like her and go from there,who knows,she may be the perfect fit.