On the 1940 census there is a Dorothy & Morris KRAMER living in Brooklyn.
She is 30, born Pennsylvania, bookbinder in printing shop.
He is 36, born England, operator on ladies dresses.
They have no children.
Living with them is their niece Ethel GOODMAN, 17, born Pennsylvania, salesgirl in department store.
Perhaps knowing where they lived in April 1930, and that no children are listed as living with them, will help you figure out if the person you found on the manifest is the one you seek, or not.