sw K frame revolver

hello all, I am trying to find out the value of a revolver that my mother-in-law is thinking of selling. I belive it is a k frame,it has a 4"bbl. with a full length lug and is chambered for .32 H&R magnum. It has sw factory grips on it,but are not original. She thinks the gun is about 15 to 20 yrs. old.It is in good shape, has normal ware on the hammer and trigger and has a light line wore into the blueing aroud the back of the cylinder.I hope this is enough info.many thanks in advanced