"Your characters need to grow up if you want to do Junior Series or Middle-Grades."
This was one of the many advise I got from mentor Cecilia Yung, Art Director at Penguin Young Readers Group.
Yes, yes, yes, yes, yes. I love to read Junior Series and Middle-Grades and would love too to illustrate for these books. This is why I started reading and studying many of the illustrations of these genres, in addition to working on my picture books.