but I’m only half hearing her. My body is braced

[sobhan]

Downstairs, while I boil the kettle I make small talk with Cathy, listening to her going on about the new place in Northcote she’s discovered for lunch (“really good salads”) and how annoying the new woman at work is. I smile and nod, but I’m only half hearing her. My body is braced:
what does "but I’m only half hearing her. My body is braced" mean?
Source: The Girl On The Train, Paula Hawkins

 

[suzi br]

I'm only 1/2 hearing means she is not listening with her full attention.
Her body is braced means she is uptight, waiting for something else (nasty) to happen. It is defintion 6 of brace in our dictionary.

 

[sobhan]

I'm only 1/2 hearing means she is not listening with her full attention.
Her body is braced means she is uptight, waiting for something else (nasty) to happen. It is defintion 6 of brace in our dictionary.

thanks