Launching their second picture book, Twin Cities writer Kevin Kling and Duluth illustrator Chris Monroe posed for photos, read and signed copies Saturday at Wild Rumpus Bookstore in the Linden Hills neighborhood of Minneapolis. “Big Little Mother” is about Kling’s relationship with his sister. Kling and Monroe’s previous collaboration was “Big Little Brother,” published in 2011. The inspiration for that one? Kling’s relationship with his brother.