Marianna was born in 1806, in 1884 she was 78 years old widow. She did not marry again. Maybe she is recorded under other name. Some mistakes happened.
Paweł and Marianna had 9 children: Antoni, Ludwik, Marianna, Franciszka, Florentyna, Stanisław, Marcjan, Anna Joanna 1844-1878 (your great-grandmother) and Paweł.
Paweł was born 1804, his father Maciej was a shoemaker. Maciej married Marianna Rochowicz in 1803. Maciej died in 1843 (age 70).
Anna Joanna married Teodor Kosin in 1862. They had 6 children: Wincenty, Władysław, Helena, Stanisław, Bronisława and Antoni.
Here you can find some more information about your ancestors. This was written by your long distance cousin.
http://mazowsze.hist.pl/36/Hacked_By_Ali_ShadowDz/997/2013/3...