Every father should be so fortunate in his sons. Congratulations on both your children and your gun.
That is a .22/32 Heavy Frame Target model that dates to about 1926. This model is also referred to as the Bekeart model because a San Francisco firearms salesman by that name persuaded S&W to offer a .22 caliber version of their .32 caliber revolver.
These guns are not exactly rare, but I would say they are not common in the very nice condition that I think I see in the photo of your gun.
Excellent!
David Wilson