Fortunately, there was only one Eva living in Marlboro in 1930!

1920 United States Federal Census
Name: Nathan Liss
Age: 26
Birth Year: abt 1894
Birthplace: Russia
Home in 1920: Richmond Assembly District 2, Richmond, New York [Staten Island]
Race: White
Gender: Male
Immigration Year: 1907
Relation to Head of House: Head
Marital Status: Single
Father's Birthplace: Russia
Mother's Birthplace: Russia
Home owned: Own
Able to read: Yes
Able to Write: Yes
Occupation: Store keeper, grocery
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Eva before their marriage??

1920 United States Federal Census
Name: Eva Gordon
Age: 22
Birth Year: abt 1898
Birthplace: Russia
Home in 1920: Bronx Assembly District 4, Bronx, New York
Race: White
Gender: Female
Immigration Year: 1915
Relation to Head of House: Boarder
Marital Status: Single
Father's Birthplace: Russia
Mother's Birthplace: Russia
Able to read: Yes
Able to Write: Yes
Occupation: dressmaker
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NY Marriages--Certificate # 2504

Liss Nathan May 29 1920 Bronx
Garden Eva May 29 1920 Bronx
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1930 United States Federal Census
Name: Nathan Liss
Gender: Male
Birth Year: abt 1894
Birthplace: Russia
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Marital Status: Married
Immigration Year: 1907
Relation to Head of House: Head
Spouse's Name: Eva Liss
Father's Birthplace: Russia
Mother's Birthplace: Russia
Occupation: Merchant, general

Name: Eva Liss
Gender: Female
Birth Year: abt 1899
Birthplace: Russia
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Marital Status: Married
Immigration Year: 1914
Relation to Head of House: Wife
Spouse's Name: Nathan Liss
Father's Birthplace: Russia
Mother's Birthplace: Russia

Name: Martha Liss
Gender: Female
Birth Year: abt 1921
Birthplace: New York
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Marital Status: Single
Relation to Head of House: Daughter

Name: Sylvia Liss
Gender: Female
Birth Year: abt 1924
Birthplace: New Jersey
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Marital Status: Single
Relation to Head of House: Daughter

Name: Sidney J Liss
Gender: Male
Birth Year: abt 1926
Birthplace: New Jersey
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Marital Status: Single
Relation to Head of House: Son

Name: Philip Silberstein
Gender: Male
Birth Year: abt 1897
Birthplace: New York
Race: White
Home in 1930: Marlboro, Monmouth, New Jersey
Relation to Head of House: Boarder
Father's Birthplace: Russia
Mother's Birthplace: Russia
Occupation: Merchant, grocery
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Haven't been able to locate them yet in the 1940 census.