Bertha Elisabeth Sonnenberg was a daughter of Adolph Sonnenberg from Hamburg (1855) and Carolina Wolff from Steenwijkerwold (1864). This couple married in Haarlem on 15 August 1894 and had five children in total, of whom a stillborn son in 1895 in Rotterdam.
A sister of Bertha was Helena Dorothea, born in Den Haag on 24 July 1899. She lived however at 2nd Helmersstraat in Amsterdam where she passe…