Consider giving the princess this gift or that one for her christening. Give her both. Realize that the fairies are going to have a quarrel at one point about her use of them. And then someone will exploit them, or attempt to.
John Gardner once sagely observed that writing exercises were good practice because they were like the writing life, much of which consists of inventing stuff not because you particularly want to but because it is vitally important for what you really want to write.
Our hero is returning in triumph from his quest and going from success to success --
No.
He's going success to nerve-wracking attempt to success. It's too long a sequence to carry about without peripeteia. Even haiku and sonnets often have reversals going because it's so powerful a tool.
Denouement is all success but then it's a single scene.
I have the beginning up to the point at which the team forms and knows what villainess they face (and are aware there's two more in existence, though they do not realize how they will actually interfere with the problem).
Was reading a book recently and the end fell flat.
Part of it was that even though we had followed the villainess's point of view periodically for much of the book, we got only her narrow planning for each stage of the plot, and then, at the end, it was revealed it was not only an objective of pure selfishness, it was incredibly petty and small.
You can get away with a short denouement, if you want to pull it off. But the climax of the story should be a drama with a length that fits the rest of the story.