Carri Williams is accused of beating and starving her 13-year-old adopted daughter to death in May of 2011.
Williams described how the young girl was not given meals as punishment, and detailed the final moments before she found the child's lifeless body in her backyard.
She was composed during most of her testimony, but broke down when talking about the day she found her daughter Hana dead in the backyard of her Sedro-Woolley home.
The day Hana died, prosecutors say she was banished to the back yard. It was raining hard, and the family found her unconscious in the mud a short time later.
"My daughter was completely naked, and just her shoulders and head were on the patio face down," Williams said. "Her face was completely flat in the mole hill."
Although Hana died of hypothermia, there were other contributing causes to her death, including severe malnutrition and chronic gastritis, doctors said.
Throughout her testimony, Williams used the word "oppositional" to describe the behavior of her adopted children.
"Usually I gave her jobs that would take 20 minutes at the most. Sometimes she would be oppositional and take 2-3 hours," Williams said.
She used boot camp methods for discipline, and on numerous occasions forced Hana to sleep in a shower, nursery closet, and a barn for stealing food.
Williams says she bought a portable toilet after Hana smeared bodily fluids on bathroom walls, and also made the young girl use an outdoor shower when the girl's behavior was not acceptable.
She gave the children frozen vegetables, wet sandwiches, and sometimes no food at all for their bad behavior.
The Williams' other children told investigators that Hana sometimes was beaten with a switch for standing more than 12 inches away from where she was told to stand or for speaking without permission.
Larry Williams, Carri's husband, took the stand for most of Tuesday, describing discipline techniques the family used.
A witness told investigators that the Williams got their ideas for the disciplinary measures from a book, "To Train Up Your Child," which recommends switchings with a plumbing tool, cold water baths, withholding food and putting children out in cold weather as forms of punishment, court documents say.
When asked by an attorney what he felt most responsible about, Larry Williams replied: "I'm the dad... my daughter died... possibly I could have done something to stop it. And I didn't."
Hana had been adopted from Ethiopia in 2008 as a diseased little girl to begin a new life with her new parents in America.
Carri and Larry Williams have other biological children, who prosecutors say did not suffer the same abuse as the two adopted kids.
Hana's death also played a prominent role in a report ordered by the governor's office on the severe abuse of adopted children. The state doesn't do any background checks or home checks on international or private adoptions, and is looking into standardizing those procedures.