How did Beauty save Ginger from the fire?

James led Beauty out of the burning barn first and went back for Ginger. Ginger said she'd never have had the courage to leave if she hadn't heard Black Beauty outside.

A tall, broad man stepped forward and took me, and James darted back into the stable. I set up a shrill whinny as I saw him go. Ginger told me afterward that whinny was the best thing I could have done for her, for had she not heard me outside she would never have had courage to come out.