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.
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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."
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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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