My Great-grandmother's Pocket Watch

This watch belonged to my great-grandmother. It is 35 mm in diameter, 18 K gold, winds with a key. Has a bullseye crystal. My great-grandmother was born in 1862 and died in 1937. She lived on a farm in Mississippi. From what research I have done on this watch, it is European made. How did my great-grandmother get such a fancy watch? I think maybe her mother brought it over when she immigrated to the USA from Austria in 1850. I know that it is old. Must have been made in the early 1800's. I also have an oil painting of my great-grandmother, and I have heard many stories about her. I really like the one where she saved my mother's life when my mother had "whooping cough" at 6 weeks of age. I will pass this treasure on to my daughter one day. I just wish I knew more about it.