The Country Wife II

Pinchwife, in an attempt to control his wife, forces her to write an abusive letter to Horner: "Write as I bid you, or I will write 'whore' with this penknife." We've seen characters try to manipulate letters, and the exchange of them, but this attempt is especially fierce and contemptuous. If his attempt clearly is a metaphor of his desire to control and shape her inner life, what does her manipulation of the documents illuminate about subjectivity, interiority, and gender on the Restoration stage?