It's Just So... adventurous for a little girl named Lizzy as she faces challenges of growth and change. She and her faithful puppy adopt a frail little sapling tree, taking on the job of protecting and nurturing their new, well-rooted 'friend' throughout the seasons. In the meantime, Lizzy is outgrowing all of her favorite clothes and watching as Mom seems to be outgrowing her clothes as well. Lizzy's biggest change comes in welcoming the new baby as her family tree seems to be growing too.