The reason why Edwin noticed that something was wrong with Caroline's leg wasn't because she had exposed it. It was because he was careful and paid special attention to Caroline.
Before leaving the house in the morning, Edwin had paid special attention to Caroline's outfit, so he remembered that she was wearing a pair of stiletto shoes.
The pair of shoes looked good, but they were obviously not suitable for fighting in a complex environment like the tea garden. In order to not restrict her movements, Caroline would definitely take off her shoes and fight barefooted.
The tea garden was full of soil, stones, and branches, which would definitely hurt her feet.
So, after he saw Caroline, he paid special attention to her feet. As expected, she changed into a pair of soft-soled shoes, which probably confirmed his guess.
