How can Rufus impact his mother's feelings toward Dana?

In the novel
"," by, Margaret Weylin is the mother of Rufus.  She is very protective and
overbearing where Rufus is concerned.  She dislikes Dana on the spot.  When Rufus breaks his leg
and Mrs. Weylin walks in his bedroom she sees Dana placing a pillow under his head.  She starts
yelling an screaming at Dana.  Rufus and his father calm her...