Ancestry.com
Passenger record is also available at EllisIsland for the arrivals in New York, but the Hamburg emigration record is only available on Ancestry.
I found the matching emigration record for Anna and the children leaving Hamburg aboard the Huddersfield for Liverpool, England on 28 May 1892:
Waschkau, Anna, aged 26, formerly of Kenty, Galizien (Galicia), bound for New York
Waschkau, Marie, aged 5
Waschkau, Kazimiera, aged 3
Waschkau, Ludwig, aged 1