PROVIDENCE — The murder trial of the Woonsocket woman accused of killing her 3-year-old nephew has been postponed another two months.

Katherine S. Bunnell, 23, and her boyfriend, Gilbert Delestre, 25, were charged with beating foster child Thomas J. “T.J.” Wright in their home on Oct. 30, 2004. Prosecutors say the couple, who returned home from a nightclub to find that the boy had made a mess, beat him so severely that they broke his skull and leg.

The couple is being tried separately on charges of murder and conspiracy to commit murder. In separate trials, the two are expected to accuse each other of being responsible for the toddler’s death. Bunnell’s trial was continued several times last year, and was rescheduled for Feb. 13.

Michael J. Healey, spokesman for the attorney general’s office, said Bunnell’s trial is now tentatively scheduled for April 23.

Healey said the latest continuance was granted so that defense lawyer Gerard H. Donely could line up expert witnesses.

The prosecution, which has been ready for trial for several months, agreed to the continuances due to the severity of the charges and the consequences of a conviction, he said.

“Part of our role in prosecuting cases is ensuring that every defendant gets the right to a fair trial,” Healey said.

After a weeklong bail hearing in December 2004 — one of the longest in Rhode Island history — Bunnell and Delestre were ordered held without bail at the Adult Correctional Institutions and later indicted separately.

Prosecutors have maintained that the couple acted together, taking turns beating the boy, dragging him by his wrists, dropping him on the floor, and even throwing him across the room after they returned home from a nightclub to find that Thomas, under a babysitter’s care, had made a mess in their kitchen.

At one point, Bunnell allegedly poured milk over Thomas while he lay on the floor.

Thomas’ biological mother placed the boy in Bunnell’s care while she served a six-year prison term. At the time of the boy’s death, Bunnell and Delestre were in the process of being certified by the state Department of Children, Youth and Families as foster parents.

Raising questions about the state’s screening system for foster parents, the case prompted the Office of the Child Advocate to launch an independent investigation to determine whether the state could have done more to protect the child.

The agency’s report, which was released in 2005, stated that the DCYF missed at least five opportunities to remove Thomas from the couple’s home.

Most notably, Bunnell and Delestre had a history of alcohol and drug problems, which was detailed in the DCYF’s own records. The agency also ignored a doctor’s concerns about Bunnell becoming a foster parent.

Delestre’s trial is expected to begin after Bunnell’s trial is finished.

khayes@projo.com