In 1922, Einstein received news that he had won the Nobel Prize in November. His divorce agreement promised her his Nobel Prize money. Under the terms of the agreement, the money was to be held in trust for their two boys, while she was able to draw on the interest. Based on newly released letters (sealed by Einstein's step-granddaughter, Margot Einstein, until 20 years after her death), Walter Isaacson reported that Marić eventually invested the Nobel Prize money in three apartment buildings in Zurich to produce income. Marić lived in one, a five-storey house at Huttenstrasse 62; the other two were investments.