She did not wait for his or anyone else's reaction.

In any difficult situation, people would look to her for a reaction.

He did not have to wait long for a reaction.

The young woman was still looking at him, waiting for his reaction.

He turned to look at her, and saw she was watching for his reaction.

He turned and walked away without waiting for her reaction.

He and the woman are both watching me, waiting for my reaction.

I spent a moment too long watching the girl for a reaction.

She could feel him watching her, waiting for a reaction.

Without waiting for a reaction she sat down across from him at the table.