Chicago ? A single-mother immigration activist has invoked the ancient principle of sanctuary by taking refuge in a Chicago church rather than submit to deportation to Mexico.

Elvira Arellano, 31, remained holed up for a second day Wednesday at Aldalberto United Methodist Church with the support of the congregation’s pastor. She is there with her 7-year-old son, Saul, an American citizen.

Federal officials said there is no right to sanctuary in a church under U.S. law and nothing to prevent them from arresting her. They would not say exactly, however, if they planned to pull her from the church.

Arellano is president of United Latino Family, which lobbies for families that could be split by deportation. She had been ordered to appear at the immigration office in Chicago on Tuesday morning, but instead went to her church. “My son is a U.S. citizen,” she said. “He doesn’t want me to go anywhere, so I’m going to stay with him.”