Another writer that I coached, that I didn't even charge a penny to, had a manuscript that was good but not as good as it could be, and I loved it. So, I coached him as well. 6 months post release on line, another unknown writer, made #2 of his category for Amazon book sales.
It's sometimes difficult to interpret Ms Dunham's contorted syntax, but I understood this to mean that "another unknown writer" WAS the person she coached.
Again, a few names and titles would help.