Mrs Burton is the now deceased mother of Dominic Burton whom as hinted and implied was very violent and abusive with Dominic when he was a child. in Dominic's dream she is seen as a disgusting grotesque spider monster shadowing how Dominic saw her as a kid. (Her only talking roles so far as her as a grotesque spider monster so try to drag out your words, I'll deal with the editing to make it sound demonic :))