It has certainly been awhile since I read the Anne of Green Gables stories, but I think that your fic more than does justice to them.
The best part about your story is perhaps the remarkable subtlety you are able to employ. Stella's feelings for Anne are mostly shown to the reader only in her head and her aching longing to exhibit those feelings in the physical world is what makes this story so very entrancing.
The other factor that creates a wonderful tension in the story is Stella's awareness of her difference from the other girls. She knows that her jealousy is actually unfounded in many ways because she is the only one who has such a deep cause to be jealous of Anne's caresses.
These phrases are a perfect summation of Stella's feelings and I find them incredibly insightful:
" know, I know thought Stella, wishing she was Phil or Priscilla and could reach out and put her arms around Anne, kiss her white forehead. If she was Phil or Priscilla, perhaps she wouldn't want to so very badly. Perhaps it was wanting to that made it impossible."
The bittersweet kiss that Stella receives from her idol is the only consolation that she could conceivably have had in the story. The ending is beautiful and sad. I think this is a wonderfully written story particularly because the emotion is so subtly and aptly rendered.