A blog idea for my new story.

I've been debating whether or not to do this idea using a main character from my new story but the more I think about it the more I like the idea.

Since the character is a teenage girl I thought about making a blog that's based off her journal entries as a young girl leading up to her teenage years to where the entries stop. I think it'll show how she evolves into the character she is now in the story I'm writing and will also allow me to create a solid character with a lot of backstory. I'm really looking forward to this and I feel this new book is some of my best work.

Is this a good idea? Feedback is crucial to me.