Complex sentence: The film launched the career of child actress Dakota Fanning, who was then seven years old and had only acted in a couple of small roles; she became the youngest actress to be nominated for a Screen Actors Guild Award.
Split into simpler sentences: The film launched the career of child actress Dakota Fanning, who was then seven years old and had only acted in a couple of small roles. She became the youngest actress to be nominated for a Screen Actors Guild Award.