Emma Klara Theni

Among the victims was a party made up of children and adults from the Gartz, Guthardt, Theni and Fahey families. Of six, only one survived.
Fatality — four-year-old Barbara Jane Gartz (b.1899)
Fatality — twelve-year-old Mary Dorthea Gartz (b.1891)
Fatality — forty-one-year-old Adelheid Kertscher Guthardt (b.1862), a governess
Fatality — sixteen-year-old Elise Guthardt (b.1888), Adelheid's daughter
Fatality — sixteen-year-old Emma Clara Theni (b.1886), nursemaid
Fatality — twenty-five-year-old Mary Fahey (b.1878), waitress
Survivor — thirty-seven-year-old Maud Parcells (b. c1866–), nursemaid

Evidence that sixteen-year-old Emma Klara Thoni was employed by the Gartz family is not iron clad but seems probable, chiefly because her body was identified by another woman described as a nursemaid employed by the Gartz family — Maud Parcells.
Emma was described as a nurse living at 4644 Evans Avenue in Chicago.  According to the 1903 Chicago city directory, a pair of dressmakers lived at that Evans Avenue address.  Their names were Eliza and Emma Thoni.  Same Emma?

Occupation — In 1903, the term "nurse" was used to describe babysitters as well as medical caretakers. Emma Klara wasn't old enough to have attended nursing school, so was more probably a babysitter for the Gartz children.