WOBURN, Mass. — A lawyer for an Irish nanny charged with murder in the death of a 1-year-old girl argued Friday that medical reports indicating that the child suffered bone fractures when she was not in the nanny’s care should result in the nanny being released on bail while awaiting trial.

But a prosecutor said the older injuries don’t affect the prosecution’s allegation that Rehma Sabir suffered severe head injuries during a time when the nanny, Aisling Brady McCarthy, was watching her.

“There is no question that the injury was sustained within the seven hours where the defendant was the sole caretaker,” Assistant District Attorney Patrick Fitzgerald said.

McCarthy is now being held without bail. Judge S. Jane Haggerty did not immediately rule on the defense request that bail be set at $5,000.

Her lawyer, Melinda Thompson, said that if she is released, she would be willing to be monitored by an electronic bracelet and to sign documents promising to stay in the United States to face trial.

But Fitzgerald said U.S. Immigration and Customs Enforcement officials have informed him that if McCarthy is released from jail, they are required to deport her immediately. That’s because McCarthy came to the U.S. about 12 years ago under a visa waiver program that entitled her to stay 90 days. Under that program, people who stay longer than allowed waive their right to appeal and must be deported immediately. “She will be deported without any assurance that she will return to face these charges,” Fitzgerald said.

Haggerty did not indicate when she would rule on the bail request but scheduled another status conference for Feb. 21.

Thompson argued that two medical experts for prosecutors concluded that vertebral fractures the baby had were probably about three to four weeks old at the time of her death. The baby was traveling outside the country with her family during that time period, so the injuries could not have been inflicted by McCarthy, she said.

Thompson said if the grand jury that indicted McCarthy had those reports, it could have changed the course of the investigation into the baby’s death.

“Maybe other people would have been interviewed,” she said. “It calls into question the commonwealth’s entire case.”

McCarthy, 35, of Quincy, had been the baby’s nanny for about six months at the time she died.

The trial is scheduled to begin April 7, but Thompson said prosecutors have been slow in turning over evidence and said the defense may seek a delay.