Hi Kate, Thanks for being brave for all us children book writers and jumping in the deep end! I love this: kindness is the strongest magic of all
It sounds like the heart of your story/theme and it's great.
For your pitch, try this formula: [name of main character] must [action/plot] in order to [reach desired solution]. What does your main character want and what's stopping him from getting it?
You might not get the perfect elevator pitch from this formula, but it will help you write and structure your story/plot better. At least that's what I got from writing mine. Mine is way too long, but I used it as a tool to help me see where I needed to go with the story. Here's mine:
Desperate to have a family of her own, the orphan chicken Seed abandoned her best friend and ran away. Now her eggs are missing and she has no one. On a quest to find her eggs and win back her friend, she must first come to terms with the true meaning of family.