to whom does pedro become engaged? why?

One afternoon while the women complete their various duties to prepare the sausage, Tita, fifteen years old, announces that Pedro Muzquiz would like to come to the house and speak with her about marriage. Mama Elena tells Tita that it is useless for Pedro to ask for her hand in marriage because Tita, being the youngest, is obligated by family tradition to care for her mother until death. Pedro Muzquiz and his father appear at the ranch to ask for Tita’s hand in marriage. Mama Elena refuses to grant her blessing for Pedro’s union with Tita and offers Rosaura to him instead.

After the Muzquiz’s depart Mama Elena comes into the kitchen to announce that Pedro will marry Rosaura.