In "In the Midst of Alarms" (1894) by Robert Barr, Renmark wanted to tell someone that his son is missing, but he didn't want to alarm the boy's sister
“Is your father in the house?”
“Yes, but he is worried about mother. Tell me what it is. It is better to tell me.”
“Don’t keep me in suspense like this,” cried the girl in a low but intense voice. “You have said too much or too little.
What does "say too much or too little" mean?