Just doing a quick lookup on Ancestry showed a possible
Catharine Mignerey and family arriving in NY on 13 Apr 1850 aboard the Adelaide
Metcalf.
Quite a few Mignerey's were on the ship - not all of them listed together. And the ones listed with
Catharine didn't appear to all be from the same family.
It "appears" the father was Jean
Georges age 53, mother Marie Goux about the same age. Brother
Jacques age 21, brother Charles age 9 -- then it gets iffy.
Complicating all of this is the tendency for the people in this area to give all their kids the same names. The ages are often approximate too.
I'm sure since the date of your first post in 2001, you've gotten much farther than this. There are severral people who have traced most, if not all, of the
Mignerey family in France/Württemberg.