The brothers constitute the total roll of the secondary department on the island of Skerries and will continue to do so if the full council agrees next Wednesday.
The council's services committee rejected a proposal from education officials to close the secondary department by 10 votes to eight. The move would have saved around pound;100,000 a year.
The committee also agreed by 11 votes to seven to reject proposals to close five small rural primaries with a total roll of 62 pupils, which would have saved pound;450,000 a year, and has asked officials to evaluate the possibility for shared management of the five schools.
Shetland has two six-year secondary schools, seven four-year secondary schools and 25 primary schools. Fifteen of these schools are staffed by one or two teachers. The council currently spends around pound;35 million annually on education, which is between pound;15 million and pound;17 million more than its allocation from the Scottish Executive.
Parents and their supporters responded with delight at the end of the committee meeting, which lasted almost four hours.