Some legal experts speculated that Specialist Hutchinson’s commanders threatened court-martial to send a message to other single-parent soldiers in the brigade. Last year, more than 10,000 single parents on active military duty deployed overseas.

Image Angelique Hughes, Specialist Hutchinson's mother, found she was unable to help. Credit... Jim Wilson/The New York Times

“It could be that they have a ton of single parents and deploy regularly and can’t afford to have disruptions like this,” said Michelle M. Lindo McCluer, a former Air Force lawyer who is now director of the National Institute of Military Justice, a nonprofit group in Washington.

In its statement, the Third Infantry Division noted that there were many other single parents or dual-military families in Specialist Hutchinson’s unit who deployed to Afghanistan. “They have experienced similar challenges but have been able to overcome them so they could deploy with their units,” the statement said.

Specialist Hutchinson’s case unfolded about the same time as the division’s commander was embroiled in another controversy. In December, the commander, Maj. Gen. Anthony A. Cucolo III, who oversees forces in northern Iraq, issued orders threatening to punish soldiers, married or single, who become pregnant. (Punishment was also threatened for sexual partners.) The general, who has sent home about eight soldiers from Iraq because of pregnancy, later backed off the threat of court-martialing such soldiers.

Raised in Oakland, Specialist Hutchinson was a member of the Junior Reserve Officers Training Corps in high school and then enlisted in the Army upon graduation. She wanted, she said in a written response to questions, “to get away from home and try something new.” Her son, Kamani, was born in January 2009.

Specialist Hutchinson declined to say anything about the boy’s father, other than that he had never been involved with Kamani. Ms. Hughes said she believed he was a former soldier.

Single parents are required to file family care plans months before deployment. In her plan, Specialist Hutchinson listed her mother as a long-term caregiver and in October she used a two-week leave to take her son to Oakland.