Michigan Death records from Ancestry.com shows Name: Mary M Leblanc Birth Date: 29 Mar 1909 Death Date: 1 Jan 1972 Residence: Alpena, Alpena, Michigan Place of Death: Alpena, Alpena, Michigan - Because you already know when and where she died ... you might want to contact the local genealogy society They might have an index of obits from the local newspapers The might have other reference books to answer your other questions.
Northeast Michigan Genealogical Society 491 Johnson Street Alpena, Michigan 49707
Serves Alcona, Alpena, Montmorency and Presque Isle Counties
--- Other stuff I found
Marriage Date: 26 Nov 1923 Marriage Place: Wayne, Michigan Groom's Name: Russell Brotz Groom's Age: 21 years - b. 1902 Groom's Birthplace: Michigan Groom's parent's: Valentine Brotz and Anna Shuster Bride's Name: Mary J. Kaiser Bride's Age: 20 years - b.1903 Bride's Birthplace: Michigan Bride's parent's: Frank Kaiser and Martha Goike This first record shows that they went to the courthouse to get the license but no marriage info was recorded ----- Marriage Date: 22 Jul 1925 Marriage Place: Detroit, Wayne, Michigan Groom's Name: Russell Brotz Groom's Age: 23 years - b. 1902 Groom's Birthplace: Michigan Groom's parent's: Valentine Brotz and Annie Schuester Bride's Name: Mary Kaiser Bride's Age: 22 years - b. 1903 Bride's Birthplace: Michigan Bride's parent's: Frank Kaiser and Martha Goike This second record has a note attached showing that they got divorced. --- I'm not sure if this is the right Mary Kaiser But is sure seems strange that another Mary Kaiser from Wayne County with parents named Frank and Martha is getting married to some other guy --- 1930 Federal Census Michigan > Wayne > Detroit (Districts 501-750) > District 676 > 5 Russell Brotz 27 Mary Brotz 26 Donald Brotz 1 year 5 months
--- Michigan Death Records from Ancestry.com shows Name: Russell F Brotz Birth Date: 16 May 1902 Death Date: 16 Dec 1978 Residence: Detroit, Wayne, Michigan Place of Death: Grosse Pointe, Wayne, Michigan - It might be interesting to get a copy of his obit from the Wayne County Genealogical Society P.O. Box 530063 Livonia, Michigan 48153
I know this stuff does not answer your questions about Mary and her husband Mr. LeBlanc.
The 1940 Federal Census will be released soon. Maybe there will be more info regarding this family
I hope this information will be helpful to your research.