WOBURN, Mass. (AP) -- An Irish nanny charged with murder in the death of a 1-year-old Massachusetts girl in her care will remain in custody while awaiting trial, a judge ruled Friday.

Middlesex Superior Court Judge S. Jane Haggerty, however, warned that she would "seriously reconsider" that decision next week if prosecutors fail to quickly turn over key medical evidence that lawyers for Aisling Brady McCarthy need to prepare for trial.

McCarthy is charged in the January 2013 death of Rehma Sabir, who was taken to the hospital with severe head injuries on her first birthday and died two days later.

McCarthy’s lawyers had requested that she be released on $5,000 bail, arguing that two medical experts have concluded that the girl suffered bone fractures three to four weeks before her death when she was not in McCarthy’s care. Prosecutors, however, argued against bail, saying that the older injuries did not contradict their allegation that the girl suffered fatal head trauma at her family’s home in Cambridge while in McCarthy’s care.

Prosecutors say DNA examination of material used to wipe the scene of the girl’s fatal head injuries show that McCarthy handled the materials, contradicting her statements that she did not know how the girl was hurt.

"Exculpatory evidence"

McCarthy’s attorneys have criticized prosecutors for failing to quickly provide evidence they need to prepare for trial and the judge appeared to lose patience with prosecutors over that dispute.

"They are entitled to have what they need," Haggerty told prosecutors, after a lengthy back-and-forth over the whereabouts of 72 medical slides that defense lawyers want to send to their experts for examination.

"Those 72 slides are basic, fundamental exculpatory evidence," defense lawyer David Meier said in court.

Defense lawyers said that because of the delays they were not prepared to go to trial, which is scheduled for April 7.

Prosecutors had submitted a list of some 90 potential witnesses, including 35 doctors. The majority of those witnesses had not testified before the grand jury that indicted McCarthy, Meier said, adding that defense lawyers would need additional time to review these new witnesses.

Prosecutors have aggressively sought to thwart McCarthy’s bail application, saying U.S. Immigration and Customs Enforcement officials have issued an order for her detention and that if she is released into their custody, they are required to deport her immediately for overstaying her visa. That problem stems from the fact that McCarthy came to the U.S. about 12 years ago under a visa waiver program that entitled her to stay 90 days. Those who stay longer than that waive their right to appeal and must be deported immediately.

McCarthy’s attorneys, however, say that she is determined to remain in the United States to clear her name at trial. She is ready, they said, to be monitored by an electronic bracelet and to sign documents promising to stay in the country to face trial.