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Not sure exactly what you are trying to find as you posted much of the information to start with, so you probably have death cert for Clara etc. It appears that many family members - Holmes, Wahl's etc immigrated to MA.
Clara is buried in Pine Grove, Lynn MA: appears from her death cert that she died from complications resulting from a miscarriage, by the medical terms used.
Olaf is found in 1910 as a widower.Household includes his children Sylvia (Solveiga), Ruth, Harold; his mother Karen Olson, his mother-in-law Agnes Wahl, several brothers and sisters-in-law, nieces, etc.
1920 living with children Sylvia and Harold
1930 living with dau Sylvia and her husband Francis Walsh and grandchildren Richard and S Ruth.
Name: Clara E Holmes Titles & Terms: Housewife Event: Death(cause incompl abortion/septicemia)- Event Date: 23 Aug 1906 Event Place: Lynn,,Massachusetts Residence: Lynn,,Massachusetts Street Address: 2 Regent Place Gender: Female Age: 31 Marital Status: Married Birthplace: Norway Estimated Birth Year: 1875 Burial Date: not given Burial Place: Lynn, Massachusetts Cemetery: Pine Grove Cemetery Father: John Wall Father's Birthplace: Norway Mother: Agnes Fehl Mother's Birthplace: Norway Spouse: Olaf K Holmes Volume/Page/Certificate Number: 201 Film Number: 2258378 Digital Folder Number: 4283002 Image Number: 00621
United States Census, 1930 Name: Francis Walsh Event: Census Event Date: 1930 Event Place: Lynn, Essex, Massachusetts Gender: Male Age: 32 Marital Status: Married Race: White Birthplace: Massachusetts Estimated Birth Year: 1898 Father's Birthplace: Ireland Mother's Birthplace: Canada Enumeration District Number: 0139 Family Number: 205 Sheet Number and Letter: 8B Line Number: 78 NARA Publication: T626, roll 899 Film Number: 2340634 Digital Folder Number: 4606996 Image Number: 00688 Household Gender/Age/Birthplace Head Francis Walsh M/32/Massachusetts Wife Sylvia Walsh F/30/Norway Dau S Ruth Walsh F/3/Massachusetts Son Richard E Walsh M/1/Massachusetts Father-in-law Olaf Holmes M/58/Norway
United States Census, 1920Lynn City Ward 6, Essex, Massachusetts Name: Olaf K Holmes Residence: Lynn City Ward 6, Essex, Massachusetts Estimated Birth Year: 1873 Age: 47 Birthplace: Norway Relationship to Head of Household: Self Gender: Male Race: White Marital Status: Widowed Film Number: 1820695 Digital Folder Number: 4301092 Image Number: 00079 Sheet Number: 19 Household Gender/Age/Birthplace SELF Olaf K Holmes M/47y/Norway DAU Sylvia Holmes F/20y/Norway SON Harold Holmes M/16y/Norway
United States Census, 1910 Lynn Ward 4, Essex, Massachusetts https://familysearch.org/pal:/MM9.1.1/M2JD-KJL Name: Olaf Holmes Birthplace: Norway Residence: Lynn Ward 4, Essex, Massachusetts Marital Status: Widowed Race : White Gender: Male Immigration Year: 1904 Father's Birthplace: Norway Mother's Birthplace: Norway Family Number: 31 Page Number: 2 Household Gender/Age/Birthplace SELF Olaf Holmes M/38y/Norway DAU Ruth E Holmes F/12y/Norway DAU Solveig M Holmes F/10y/Norway(?Sylvia) SON Harold Holmes M/6y/Norway MOTH Karen E Olson F/77y/Norway Mother-in-law Agnes Wahl F/57y/Norway Brother-in-law Harold G Wahl M/30y//Norway Brother-in-law Fritz Hansen M/25y//Norway Sis-in-lawJennie Hansen F/19y/Norway Nephew in law George B Hansen F/y 8m/Massachusetts Niece-in lawDagma W Wahl F/9y/Norway