She used the name Maria. Owned a brewery in Sarnaki, Poland.  She was the godmother of Janina Praska baptized in Warsaw at the St. Florian's Church in 1915. Picture reproduced from a booklet by Janusz W. Nowosielski and Rafal Zubkowicz: "Piwo z Nadbuzanskiego Podlasia. Browar Szummera w Sarnakach", Pivaria, 2006, ISBN 83-913719-6-4.

According to the 1930 business directory of Poland "Ksiega Adresowa Polski (wraz z w. m. Gdanskiem) dla handlu, przemyslu, rzemiosl i rolnictwa" available in digitized form, page 703/591 her husband Jozef Szummer was an owner of a brewery and a brickyard in Sarnaki, Poland:

In a postcard sent in 1945 from Sarnaki to her cousin (nephew) Wladyslaw Tarkowski who lived in Warsaw on Marszalkowska Street Number 72, she mentions an aunt of Tarkowski, Maria Jablczynska. She was in a nursing home in Wielen on the Notec River in Poland. It is not known how Maria Jablczynska was related to Maria Szummer or to Wladyslaw Tarkowski. Wladyslaw Tarkowski most probably was a son of her older half sister, Anna Tarkowska nee Szulc who married Wojciech Tarkowski in 1874.