The touching note was posted with a family photo to, of course, Facebook. They say the baby girl was born this month and aptly named August.
Part of the letter read, "The world can be a serious place. That's why it's important to make time to go outside and play. You will be busy when you're older, so I hope you take time to smell all the flowers and put all the leaves you want in your bucket now."
The couple's first daughter, Max, was born in 2015. They announced in March that they were expecting a second child.
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