From FamilySearch (via SteveMorse.org), here is the record extract for the marriage of daughter Thelma Deutsch in 1931, which gives Gussie's maiden name as Thirman:

Name: Charles Friedberg
Event Type: Marriage
Event Date: 21 Jun 1931
Event Place: Manhattan, New York, New York, United States
Event Place (Original): Manhattan, New York, New York
Gender: Male
Age: 28
Marital Status: Single
Race: White
Birth Year (Estimated): 1903
Birthplace: New York City
Father's Name: Harris Friedberg
Mother's Name: Celia Neuwirth
Spouse's Name: Thelma Deutsch
Spouse's Gender: Female
Spouse's Age: 25
Spouse's Marital Status: Single
Spouse's Race: White
Spouse's Birth Year (Estimated): 1906
Spouse's Birthplace: Hazelton, Penn.
Spouse's Father's Name: Daniel Deutsch
Spouse's Mother's Name: Gussie Thirman

Reference ID: cn 15014
GS Film Number: 1684265

https://www.familysearch.org/ark:/61903/1:1:24D4-38D

 

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Michele Lock

Lock/Lak/Lok and Kalon in Zagare/Joniskis, Lithuania
Olitsky in Alytus, Suwalki, Poland/Lithuania
Gutman/Goodman in Czestochowa, Poland
Lavine in Trenton, New Jersey and Lida/Minsk gub., Belarus