Did she own and use the home and 2 acres as her principal residence for 2 of the 5 years prior to the sale?
For the 171 acres her long-term gain is 171,000 - (200x19=3800) = 167,200. The maximum tax is 20% or 33,440.
BUT: Did she own it herself since 1947? Or did she own it with your father/her husband who may have died sometime between 1947 and 2018?
