These 'Lady Nelson' watches were imported by MZ Berger & Co of New York back in the mid - late 1950's. They also imported one called a 'Lord Nelson' for men. Note that Berger re-used that Lady / Lord Nelson name on quite a number of different watches. MZ Berger & Co still exists as a jewelry importer.
Does the old girl still work ? It would be interesting to see what movement they used inside the watch if you want to (carefully) lift the back off.