Complex sentence: Her mother, Clara Boehmer, was an Englishwoman who had been born in Belfast in 1854 to Captain Frederick Boehmer and Mary Ann West; the couple's only daughter, she had four brothers, one of whom died young.
Split into simpler sentences: Her mother, Clara Boehmer, was an Englishwoman who had been born in Belfast in 1854 to Captain Frederick Boehmer and Mary Ann West, the couple's only daughter. She had four brothers, one of whom died young.