There is a chance, that there are additional documents regarding her birth stored in Plock archive.
https://www.szukajwarchiwach.gov.pl/en/jednostka/-/jednostka/17258639
Register at above site and ask for annexes for marriage certificate 11/1843 and keep your fingers crossed.
Good luck, Irek ...

Lakiluk pisze:No to opowiedz o swojej rodzinie. Pokaż dokumenty.

As I mentioned above, I linked to the marriage document. Here it is again: https://imgur.com/a/a9obbvb

So where can I find these records? Why can't we seem to find this family anywhere?

Zacznij od sąsiedztwa. Skoro nie skonkretyzował miejsca, to znaczy, że jest mu znane.

https://www.google.com/maps/dir/09-200+Sierpc/Mi%C5%82ob%C4%99dzyn/Kozice,+09-213/Koz%C5%82owo,+09-209/Koz%C5%82%C3%B3wko,+09-209/@52.7435965,19.5924428,10.49z

I appreciate you finding this information, but ...

Hello all, first let me apologise for wriiting in English as I do not speak Polish well enough to write fully out what I am asking for.

My third great grandmother was a woman named Tekla Sobczynska Glowacki. (She married Marcin Glowacki 14 February 1843 in Sierpc, Mazowieckie, Poland) I have the ...