Maryanne, Be very careful researching your great grandmother.
My great grandparents eloped from Mechlenburg-Schwerin in 1851, and I cannot
find them listed on any P&I records. From what I have read, since the bride
did not have her father's permission to marry my great grandfather, nor did
my great grandfather own any land in Germany, their names probably do not
appear on any ship's manifest, and more than likely they had to work on board
to pay for their passage. Also, they may have changed their name from
Schmidt to Smith upon arrival in this country. Just a warning to document
very carefully. Good Luck!
Barbara