Mamie Schulze 

Note:

a) Sponsors: Heinrich Oelbaum, Minna Barkemeyer
The source for her death date (at ancestry.com) gives her name as
Mamie; as does her marriage certificate

Emma on census is likely an enumerator error. Unless could be a middle name, her sister does have two.

BORDER CROSSINGS
Name Mamie S Doria
Gender Female
Race/Nationality Mexican
Arrival Age 30
Birth Date 1887
Arrival Date 28 Dec 1917
Arrival Place Tia Juana, California, USA
Record has photo? No
Record Type Card

Name Mamie Doria
Gender Female
Race/Nationality German
Arrival Age 30
Birth Date 1889
Birth Place St Louis
Arrival Date 23 May 1919
Arrival Place Tia Juana, California, USA
Departure Contact Child Alma; Child Consuela Doria
Record has photo? No
Record Type Card

The National Archives and Records Administration; Washington D.C.; Manifests of Alien Arrivals at San Ysidro (Tia Juana), California, April 21, 1908 - December 1952; NAI: 2843448; Record Group Title: Records of the Immigration and Naturalization Service, 1787-2004.; Record Group Number: 85; Microfilm Roll Number: 05

1940 Census
San Diego Judicial Township, San Diego City, San Diego Co, CA
P12B
4640 #310 DORIA
owns home, valued at 4200
Emma, head, female, white 49, married (crossed through in pencil with a number 7 written there), highest grade completed: H4, born Missouri, resided "same place" as on 4-1-1935, not on a farm;
Ruth, daughter, female, white, 16, single, attended school, education: H3, born Missouri;
Alma, daughter, female, white, 28, single, education: H4, born Missouri

Jefferson City Post-Tribune
Jefferson City, MO
16 Mar 1949, p10
Mrs. Mina Doria, San Diego, Calif., is visiting her sister, Mrs. Adolf Niemeyer, Tanner Bridge road. Mr. and Mrs. Niemeyer and Mrs. Doria drove to St. Louis to visit Mr. and Mrs. Joseph Doria. Mrs. Doria expects to return to California in April.

The San Diego Union and Daily Bee; Friday April 26, 1957; San Diego, CA; Page 7
Mrs. Mamie Doria Rites to be Held Here
Services for Mrs. Mamie Doria, 68, of 3506 Union St., a resident here 40 years, will be at 11:30 a.m. today in Grace Lutheran Church. Entombment will be in Lewis Colonial Morturary. The family has asked that any contributions be made to the Lutheran Hour or the Lutheran Home for the Aged.
Mrs. Doria died Tuesday. She was a native of St. Louis.
Surviving Mrs. Doria are three daughters, Mrs. Kerneil Bernardini and Mrs. Frank Nottbusch Jr. of San Diego and Mrs. Andre Gomez of Deerfield, Illand four grandchildren, Diane Palmer, Kathleen Nottbusch and Betsy Ann Nottbusch of San Diego and Andre Gomez of Deerfield.