So, we know that the name Evan has come up recently as maybe being the canon name for the Bite Victim (BV). The name Evan is a biblical name, which means that all of the Afton children may have biblical names. William is also a biblical name, meaning the four canon characters of the Afton family may have biblical names. So I looked through popular biblical female names, and came across the name Christine. If Mrs. Afton had a teenage child in the 80's, that means she was probably born in the late 30's, early 40's. Christine was a popular name in the 40's. Therefore, maybe that is her name. Also, sorry if I did that in the wrong format.
