He wondered whether Mortimer had been talking.

If the pup had talked, the thing was ominous, because it implied that others knew the difficulties Cartwright might have to meet.
"Do you imagine the house needs supporting ?" he asked carelessly.
Mrs.Cartwright hesitated.

"I really know nothing about it; but don't people grumble when you can't pay them much and their shares go down?
Perhaps if the family owned a good part of the capital, you could take a firmer line." It was plain that Clara had been pondering.

Mortimer _had_ talked and somebody who was not Cartwright's friend had informed him.

Cartwright was tempted to let his wife do as she wanted: Clara owned shares in the line that he had let her buy when freights were good and she had afterwards refused to sell.