Xinis was born in Mineola, New York, graduated from the University of Virginia and went to Yale Law School. She clerked for Judge Diana Gribbon Motz on the 4th U.S. Circuit Court of Appeals. She was an assistant federal public defender in Maryland and adjunct professor at the University of Maryland Francis King Carey School of Law.

A judge on Wednesday put a weeklong pause on collecting information in Kilmar Abrego Garcia's deportation case after the Trump administration asked her to, but the details behind the judge's decision remain under seal.