Complex sentence: She finally stops denying to herself that she has loved Steve for a while and takes Timmy, boards the train Steve is taking to California (he had sent her a farewell telegram letting her know he was leaving that night for California), and embraces him.
Split into simpler sentences: She finally stops denying to herself that she has loved Steve for a while. Steve has sent her a farewell telegram letting her know he is leaving that night for California, so she takes Timmy, boards the train Steve is taking, and embraces him.