Complex sentence: Her mother took a part in writing her daughter's character Sandy out of "Holby City"; in the episode, which was broadcast in September 2003, her character won the lottery and subsequently emigrated to Australia.
Split into simpler sentences: Her mother took part in writing her daughter's character Sandy out of "Holby City". In the episode, which was broadcast in September 2003, her character won the lottery and subsequently emigrated to Australia.