What happened to Gertrude Schuyler? Why did this happen?

The day after Charles' death, Gertrude Schuyler and her family were at a resort across from the spot where the shark had killed Charles Vansant. Gertrude was unaware of the incident and that a killer shark was stalking the coast line. There were some 50,000 people in the water the day following the attack on Charles Vansant. As Gertrude stroked along parallel to the coastline, she was suddenly pulled under water. She resurfaced and screamed just once. Lifeguards and volunteers fortunately heard her and in minutes were able to rescue her. Miraculously, she was not injured, although she nearly drowned. Gertrude had gone for a swim, not knowing about Charles because nothing had appeared in the paper yet and word about the attack had not spread.