Hurray for dreaming up new characters! I don't know whether or not I was asleep when I thought of the story but I new I had to write it down somewhere so here goes.
She's a fairy, or spirit, or ... thing, I dunno. But she doesn't really have a shape. She started as nothing, but she lived in this room with a boy and she has a crush on him. (No, the boy wasn't me, even in dreams I'm thoroughly ignored.) So as her feelings grow she finds that she has the ability to change shape. But it's slow and takes a lot of effort. This is her primary form which she subconsciously grew and thus takes the least effort to maintain.
Her human side resembles the boy's mother, the only other human she had seen before the start of the story, her body is that of a horse because the boy collects toy horses, and she has a tail of a bee and insect wings because... I guess she was on a window sill or something. She has male genitalia because she's only ever seen the boy naked so she thinks its natural (AWKWARD PLOT INSTALLMENT XD) She can change shape easier with emotion, like when she's mad she'll get really thin and snake like or when she's really happy she'll grow feathers and light breezes send her sailing.
SO the main aspect of the story: The boy for some reason knows and accepts her existence, they hang out and stuff, but she's shy of other people so only the boy knows she exists. Yah so, the boy knows she exists but for some reason is oblivious to her feelings for him and she's been casually growing, changing shape, trying to find a way to be acceptable to him and tell him her feelings. THEN the boy gets a sudden popularity boom at school and starts hanging out with real people and this puts a lot of pressure on the fairy to compete for his attention. She she causes a lot of mischief for him and the people around him.
I think that's all the details I have worked out right now. I suppose the underlying theme would be about a boy growing up and having to choose between fun make belief things and the real world that isn't as pleasant but also requires his attention... but I just thought of that right now...
Much done before 8am.
If someone likes this they can feel free to take it from here, it might be another decade or two for this story to get on my priority list.