Complex sentence: The family were then provided for by William Daw, Elizabeth's brother-in-law, a prosperous lawyer who arranged Bellingham's appointment as an officer cadet on board the East India Company's ship "Hartwell".
Split into simpler sentences: The family were then provided for by William Daw, Elizabeth's brother-in-law, a prosperous lawyer. Daw continued to sponsor him, and secured him an appointment as an officer cadet on board the East India Company's ship "Hartwell".