Shame is the personification of sexual morality within the woman courted by the narrator. She is dressed and veiled like a nun and is the daughter of Reason and Trespass, although she is conceived immaculately, as Reason would never be intimate with anyone (or anything) as hideous as Trespass.
Shame has been sent by Chastity as the keeper of the rose bed, but she is continually attacked by Venus (sexuality.)