[Jack's mother] rarely spoke above a mutter (26.11).
Jack's relationship with his mother is almost as troubling as the one with his father. She was unable to protect her children or herself from her husband. Although not explicitly stated, she doesn't even seem to try. Since she isn't developed beyond this, it's hard to know exactly why she's so passive.
In those days it did not seem strange to Jack […] that his own love should go hand-in-hand with his fear […]. (26.11).
Jack is thinking about his relationship with his father. King takes care to explore the coexistence of love and fear through this relationship. Can we relate to what he's talking about? Are most parent-child relationships characterized, to some degree, by this coexistence?
"You're just like my mother, you milksop bitch." (46.69)
Wendy isn't really much like Jack's mother. Milksop, obviously refers to his mother's passivity. Wendy is anything but passive. When Jack says Wendy is like his mother, he means she's betrayed Jack the way he thinks his mother betrayed his father. He only thinks his mother betrayed his father when he's lost himself to the hotel.