What was the relationship between Tara and her mother?

Tara admired her mother, Faye, while she was growing up, even when her mother was refusing to protect her from her cruel brother. Once Tara moved away from the family and worked to get an education, however, cracks form in the relationship. Her mother refuses to see her now because Tara won't see her father, and Faye considers it an insult to her husband to go against his wishes.
Tara's mother was a reluctant midwife; she did the job and then came home pale and shaken. She wanted to quit, but her husband insisted that she continue, and then the only other midwife moved away. Tara says she was the only midwife for 100 miles then. The job changed her; she had her own money and some personal power for the first time. She used some of the money to purchase things to improve her midwifery.
When Tara attends a birth with her, she says she saw her mother's secret strength for the first time. However, her mother also often refuses to refute her husband's outlandish beliefs. She also still doesn't protect Tara from her cruel brother.
However, after Tara got an education and didn't believe everything her parents said with impunity, there was some tension between them. For example, when Tara insisted that her father not stand up and rebuke her professors at an awards ceremony, her parents refuse to come see her get the award. This causes problems between them that didn't exist when she was a child. She questions her mother and doesn't take everything at face value anymore, so they are less close. The following exchange provides an example:

"That doesn’t matter," she said. "I’ll adjust the chakra on Audrey and wing it to you.""You’ll what it to me?""Wing it," she said. "Distance is nothing to living energy. I can send the corrected energy to you from here.""How fast does energy travel?" I asked. "At the speed of sound, or is it more like a jetliner? Does it fly direct, or will it have to lay over in Minneapolis?"Mother laughed and hung up.

Despite the tension, it's clear that they still care about each other. Later, her mother apologizes for not being a better parent, and this helps heal the rift between them more than before, yet her mother doesn't then back up the words with actions. She takes up for Shawn again, even when he directly threatens to kill Tara. She tells her that the night Shawn killed their dog, Tara's anger was actually more dangerous than Shawn.
When Tara returns home to try to reconcile with her mother, she sees an email her mother wrote saying that Tara has been taken by the devil. She tries to reconcile with her parents, but she ends up cutting off contact with them. Later, she reaches out to her mother and offers to see her without her father. Her mother responds. She writes:

Mother’s message amounted to an ultimatum: I could see her and my father, or I would never see her again. She has never recanted.

So, ultimately, Tara's relationship with her mother is not good. They are not on speaking terms. Tara still writes to her mother and asks to see her without Tara's father, and her mother always quickly refuses.