Complex sentence: By 1938, however, they helped Eslanda's brother Francis to escape, her brother John had already departed the year prior, and Paul Jr. did not continue with his education at a Moscow "model school".
Split into simpler sentences: By 1938, however, they helped Eslanda's brother Francis escape. Her brother John had already departed the previous year, and Paul Jr. did not continue with his education at a Moscow "model school".