At the end of the Second World War she and her parents left Oppeln, which became part of Poland; they relocated to Ansbach.
[3] After schooling, Mainka worked for five months in a copy center, and became involved as an editorial assistant in the production of short documentary films by Harry Piel.
Mainka's long collaboration with Kluge began with Porträt einer Bewährung (Policeman's Lot) (1964), and extended through 1986 including the films Yesterday Girl (1966) and Artists Under the Big Top: Perplexed (1968).
Following her final film with Kluge, Miscellaneous News (1986), she retired into private life; the New German Cinema era was over.
Mainka-Jellinghaus is among the editors interviewed for the 2006 documentary Schnitte in Raum und Zeit (Cutting in Space and Time), which was produced by Gabriele Voss.