Screamer not Joan O'Brien
In his commentary "Pretty Good John Wayne Vehicle" Jay Bird tentatively identified the actress playing the screaming woman as Joan O'Brien. In fact,it was Ann Barton in the role of the pregnant Mrs.Schofield who let out the scream.
Joan O'Brien played Jake Cutter's love interest Melinda Marshall. John Wayne's daughter Aissa played Melinda's young daughter Bessie. This was the second movie in which Joan O'Brien and Aissa Wayne played mother and daughter. The previous year the pair had played the wife and daughter of Capt. Dickinson in "The Alamo".