As most of the earliest generation of women to study at Swedish universities,[2] she came from a well-to-do bourgeois background, daughter of Anders Olof Eschelsson, the owner of a soap factory who also served as Prussian consul in Norrköping.
Elsa's mother Carolina Lovisa Ulrika Frestadius was her husband's cousin and daughter of a prominent Stockholm industrialist, A. W.
At the age of fourteen Elsa lost her father as well and moved in with an older sister, the young dowager countess Anna Piper.
She has been described[4] both as shy and ambitious, and as a sensitive person with many highs and lows who kept a formal and distanced relationship to the other women at the university and avoided participating in many of their social activities.
In 1997, at the occasion of the 100th anniversary of her disputation for the Doctor of Laws degree, a volume of the yearbook De Lege, was published under the title Elsa Eschelsson: Ad studium et ad laborem incitavit, including a biographical study of Eschelsson by Gunilla Strömholm and other papers by female jurists at the Uppsala Faculty of Law.