Early life and education
Whitney was born on September 11, 1847, in Waltham, Massachusetts. Her mother was Mary Watson Crehore and her father was Samuel Buttrick Whitney. Her father was successful in real estate and wealthy enough to provide her with a good education for a woman at the time. She went to school in Waltham where she excelled in mathematics and graduated from the public high school in 1863. She was privately tutored for one year before she entered Vassar College in 1865, where she met the astronomer Maria Mitchell. During her time at Vassar College, her father died and her brother was lost at sea. She obtained her degree in 1868.
In the years 1869 to 1870 she took some courses about quaternions and celestial mechanics by Benjamin Peirce (at Harvard). At the time, women could not be admitted to Harvard so she attended as a guest. She obtained her master's degree from Vassar in 1872, afterwards she went to Zürich for 3 years where she studied mathematics and celestial mechanics.