“When I call him,” Ms. Izhar said, “he starts crying and complains to me — ‘Why don’t you take me to Malaysia? You always say that you will bring me there soon. How much longer will you keep cheating me?’”

Ms. Izhar left Jubair, her eldest child, in part because she could not afford the smugglers’ fee, which cost much more for young men, but she had hoped to be able to have him rejoin the family. She felt compelled to flee persecution in Myanmar, she told The Times last year, but vowed when she left, “If I can stay alive, I will bring him to Malaysia.”

That goal has remained out of reach. Myanmar does not recognize Rohingya as citizens and does not allow them to leave. Smuggling has become even more difficult since governments in the region cracked down on the trade after it exploded into a crisis last year.

Nor can Ms. Izhar return to Myanmar even to visit, because she arrived in Malaysia as an undocumented migrant. Not only would any journey abroad be perilous, it would be nearly impossible for her to return legally to Myanmar.

She has phoned Jubair occasionally and sent money, but he has not found stable work or a warm home, though he is staying with one of her brothers, an instructor in Islam who has also been unable to find steady work.