A Big Hand for the Little Lady (1966)

A naive couple and a child arrive to the town on the way to San Antonio, Texas to buy a farm there. There is a poker game between the richest men in the region. The man cannot resist it and though he is a very bad poker player, enters the game betting all the money of his family. In the climax of the game he suffers a heart-attack. His wife then takes his place in the table. That's the only way of recovering their savings. But there is a little problem. Can anybody explain her how to play poker?