Complex sentence: Prince Vsevolod and his sister were safe under the care of their grandmother in the Marble Place.For a time, they lived a precarious existence, and his grandmother was forced to secretly sell family heirlooms to provide for the family.
Split into simpler sentences: Prince Vsevolod and his sister were safe under the care of their grandmother in the Marble Place. Their grandmother was forced to secretly sell family heirlooms to provide for the family.