It has been an emotional start to the new year for Rocio Rebollar Gomez and her family.

On Thursday, after 31 years in the United States, a country where she had built a life and raised three children, including a son now in the United States Army, Ms. Gomez was deported to Tijuana, Mexico, where she had little family left.

That son, Second Lt. Gibram Cruz, 30, who has been in the Army for five years and rushed to be with her the day after Christmas, said he was “shocked” at the way his mother was treated and called the actions by Immigration and Customs Enforcement “completely inhumane.”

Ms. Gomez, 51, was previously scheduled to self deport and that plan was known to ICE, the family’s lawyer, Tessa Cabrera, said on Friday.

Instead, as the family went to an ICE office to discuss her case, Ms. Gomez was taken across the border to Tijuana without a chance to say goodbye, Ms. Cabrera said.