Hedwig Oppenheimer

Hedwig and Jacob had two daughters only, Gertrude and Bertha. Bretel is merely a nickname for Bertha, thus the same person.

Source: Calzareth extension of the Michelfeld tree (Oppenheimers). 2) Ein Amerikaner, a collection of andecdotes in the life of Harry (Heinz) L. Ettlinger by H.L.Ettlinger.

Harry Ettlinger is the first cousin once removed of Bertha Oppenheimer.

Jacob Oppenheimer married a Wälder, so his mother in law could not have been an Oppenheimer as pictured below.

Source for life & family:

Oppenheimer Eine jüdische Familie aus Bruchsal by Thomas Adam, Thomas Moos & Rolf Schmitt

ISBN: 978-3-89735-747-1 Page 91 ff.

cf.: https://de.wikipedia.org/wiki/Liste_der_Stolpersteine_in_Bruchsal