Kathleen Crocetti had hoped to deliver a mural to a community center in Gaza, where a pro-Palestinian freedom march is planned for New Year's Eve.
Crocetti and her husband, Bill Lucas, have been ordered not to leave the hotel where they are staying, about 30 miles from Gaza, without a police escort.
They have not been charged with any crimes.
Crocetti was part of a group of people sent to Gaza by the anti-war organization Code Pink, which also launched this demonstration at the Egyptian consulate in San Francisco.
Two code pink members staged a hunger strike to protest an Israeli retaliation attack on Gaza, in which they claim 1,400 Palestinians were killed or injured last year.