Cynthia Marshall 
The Adventures of Princeton & Ava-Paisley [EPUB ebook] 
Are We Ready for Bed?

Princeton and Ava help each other while learning the basics to daily life lessons. Princeton and his little sister Ava learn to understand that following their bedtime will help them to get the rest they need and allow them to have more energy during the day. They work together to make bedtime a priority and understand that a proper bedtime is important. As siblings they will always have to help each other through their adventures.