why might the author have decided to name one of the girls Triolet (a French verse form)? What does that choice of name suggest about the character of Triolet?

Explanation:

I think the author decided to name one of the girl Triolet due to the meaning she had in the story. As soon as Triolet was introduced she told us her love for the poem. It made her as a character seem more beautiful and mysterious, as Enn told us she was. She said, "We knew that it would soon be over, and so we put it all into a poem, to tell the universe who we were, and why we were here, and what we said and did and thought and dreamed and yearned for.

each poet admires poetry

they each admire poetry because they could just use an expression or verbally just say you but they both write in in poetry which shows they know how to write in poetry.