Harriet Stratemeyer was born in Newark, New Jersey, on December 12, 1892, the daughter of Edward Stratemeyer and Magdalena Van Camp. At a young age, Adams wanted to break free from being a "proper, young lady who should stay at home". She climbed trees, made friends with local boys, and loved books from an early age. Adams graduated from Wellesley College in 1914. Her father forbade her to work outside the estate, so she edited manuscripts at home. In 1915, she married Russell Vroom Adams, and raised four children, becoming involved in the family business only after her father's death. She resided in Maplewood, New Jersey, and in Pottersville, New Jersey, an area within Tewksbury Township.