When your family goes through a major shift, it helps to hold onto the facts. After her parents divorce, Bea starts keeping a list in her green notebook of all the things that will stay exactly the same. The very first and most important rule on her list is that her mom and dad will always love her, and they will always love each other. Now, Bea's dad is getting married to his boyfriend, Jesse, and Bea could not be happier. She adores Jesse, and the upcoming wedding means she will finally get the one thing she has always dreamed of having: a sister. Even though she has never actually met Jesse's daughter, Sonia, Bea is absolutely positive they will be best friends right away. But as the wedding day draws closer, Bea discovers that blending families is not always simple. Navigating new relationships brings unexpected questions, big feelings, and wonderful surprises. This warm and honest story explores the beautiful complexities of modern family life, showing how love can expand to make room for everyone when you keep your heart open.