Complex sentence: When she had not returned home by 5:30 p.m., her father paid a visit to her aunt, who said she had left at around 4:45 p.m. A friend had seen Page outside a chemist's.
Split into simpler sentences: When she had not returned home by 5:30 p.m. her father went to her aunt's to see where she was. Her aunt said she had left at around 4:45 p.m. A friend had seen Page outside a chemist's.