The Secret Notes of a Mugge

She was just living a regular mugge life, except being amazing at it. So for 50 years, she's writing herself secret notes in these books. Two of them are the same, and then the last one is different. And i had guessed that it was some sort of, like a one time pad where, if you start, would like the word juniper, and rotate the letters. But now i'm unsure. We got two messages to read. I pulled them both out case the're important.