In my opinion, Patricia is the character that goes through the most dramatic changes in the novel. Patricia changes from religious, to being in love, to losing a child, to losing her faith, to regaining her faith on a pilgrimage, to being a devoted mother, to being a committed member of the movement against Trujillo.

While quite young, Patricia is entranced by the nuns and the religiosity of their Roman Catholic faith.  She longs to be one of them.  Of course, this is where young love enters the scene and, at the tender age of sixteen, Patricia falls in love with Pedrito González while she washes his feet in the context of the ritual washing during Holy Week in the Roman Catholic Church.  They quickly marry and have two children.  However, when Patricia's third child dies, she loses her faith and doesn't regain it until going on a religious pilgrimage.  Patricia becomes a devoted mother through this time and worries about her children, especially when they become involved in the movement against Trujillo.  Patricia makes another transition when she moves the meetings of the movement from "near" her home to "in" her home.  This puts the family at risk.  Patricia is eventually killed as a result of her devotion to the movement.

Patricia's journey, then, is a complex one that involves religion, motherhood, and politics.  Here is a quotation from Alvarez that is important to remember in the context of this journey:

A novel is not, after all, a historical document, but a way to travel through the human heart.

How does Patria change in In the Time of the Butterflies?

The Chapter you need to look at to find the moment of change for Patria that transforms her from a good, law abiding citizen who will not support the rebel movement to a woman who is willing to oppose Trujillo's regime comes in Chapter Eight. This clearly is a moment of transition for Patria, as she observes the slaughter and capture of some rebel soldiers by government forces that completely changes her opinion of her role in the resistance. Note how Patria explains her transformation:

He was a boy no older than Noris. Maybe that's why I cried out, "Get down, son! Get down!" His eyes found mine just as the shot him him square in the back. I saw the wonder on his young face as the life drained out of him, and I thought, Oh my God, he's one of mine!

It is this identification that Patria feels with this young soldier with one of her own children that makes Patria leave this experience "a changed woman," carrying the dead boy as if it were her son. This is when Patria feels she can no longer sit back and watch her country being treated in such a terrible way by Trujillo:

I'm not going to sit back and watch my babies die, Lord, even if that's what You in Your great wisdom decide.

From this point on, Patria is a committed member of the rebel movement, joining her other sisters in their opposition to Trujillo.