In 1941, she married John "Chip" Cheesman Harkness, also a co-founders of TAC, and they had seven children.
She lived in Lexington, Massachusetts, at Six Moon Hill, a community dwelling designed by TAC.
When introducing the Study Unit to the school, a choice was made that two-thirds of the students would have a Carrel and one-third would not.
The Carrels were placed with the storage units, this allowed students to choose between working with their table-mate or independently.
All the students' belongings were in their Carrel, including coats which were hung on pegs at the end of the storage units.
[5] Sarah P. Harkness and Jean B. Fletcher were the only two female founding partners of TAC.