"Thank you so much," she told the judge during her brief appearance.
Vaillancourt remains in the Salt Lake County jail on two felony obstruction of justice charges following the death of Draper police Sgt. Derek Johnson.
Her then-boyfriend Timothy Troy Walker, also 34, is accused of gunning down Johnson as he stopped to check on the pair. Walker then turned the gun on Vaillancourt and then shot himself in jaw.
Walker, who did not have a court appearance Tuesday, has been charged with aggravated murder, for Johnson's death, attempted homicide for Vaillancourt's injuries, and several other felony weapons-related charges.
According to charging documents, Johnson, 32, was in a marked Draper City police vehicle at about 6 a.m. on Sept. 1, when he stopped at 13200 South Fort Street and noticed Walker standing outside his Volvo.
Authorities said Walker had stopped the car because he ran out of gas and the passenger-side front tire had gone flat from driving over a curb, a stop sign, a large rock and then through at fence at 13800 S. 933 East, court records show. He then continued driving a few blocks away to the area of 13200 South, police said.
When Johnson pulled up near the Volvo to see if he could help, Walker allegedly shot Johnson through the open front passenger side window of Johnson's police vehicle.
Johnson was struck in the chest by the bullet and tried to drive away northbound. Walker, who was allegedly under the influence of methamphetamine at the time, fired at least three more shots, which struck Johnson's marked vehicle, court documents state.
Johnson died a short time later.
Vaillancourt will next be in court April 8 for a scheduling conference.
Walker has a scheduling hearing in February.