Referring to her son Jeremy's battle with cancer, LeBrie said, "We fought together, me and Jeremy."
When asked if she had done everything possible to save her son's life, LaBrie declined to comment.
"I'm not going to answer that question," she said. "I think my story will come out at trial."
The boy's father, Eric Fraser, told reporters in 2009 he did not know of any religious beliefs or any other reason why his ex-wife would withhold treatment.
"I have no idea," Fraser said before LaBrie's arraignment.
LaBrie shook her head as Assistant District Attorney Kate MacDougall said she repeatedly failed to fill prescriptions for her son and deceived his doctors into believing she was giving him the medications he needed to save his life.
Fraser, 38, of Saugus, said Jeremy was a happy kid who enjoyed riding dirt bikes and swimming at a family cottage in Tamworth, N.H.
Before the arraignment, Fraser declined to speak specifically about the case against LaBrie, other than to say, "I am relieved that it is moving forward."
LaBrie faces up to 40 years in prison if convicted.