Since you are going back to 1794, your best chance is church records.
If that cemetery is related to a specific church, you should start with
that one, seeking both the burial record of that woman and baptism
records for that period (and as much as a year or two later for the
baptism). If the cemetery is not church-related or if no records for
this name are found at the related church, you would then have to learn
what churches existed in or near that town and seek their records.
It sounds like you are thinking that your ancestor was born to this
sister-in-law and adopted/ raised by relatives when she died? If so,
there might also be guardianship records for that town.
[Non-text portions of this message have been removed]