Complex sentence: Her first efforts, begun on her first day in residence with the help of society decorator Sister Parish, were to make the family quarters attractive and suitable for family life, by for example adding a kitchen on the family floor and rooms for her children.
Split into simpler sentences: Her first efforts, begun her first day in residence (with the help of society decorator Sister Parish), were to make the family quarters attractive and suitable for family life. Among these changes was the addition of a kitchen on the family floor and rooms for her children.