...just looking at this image makes me want to reach out to her and tell her...  There is an option,

²⁸ “Come to Me, all who are weary and burdened, and I will give you rest. ²⁹ Take My yoke upon you and learn from Me, for I am gentle and humble in heart, and you will find rest for your souls. ³⁰ For My yoke is easy and My burden is light.”

Jesus Christ (Matthew 11:28-30)

So who came up with the slogan "Just Do It?"  

The famous Nike slogan came from a spree killer Gary Gilmore, who received the death penalty for murdering two people in Utah in July, 1976. Just before a firing squad did their duty, Gilmore was asked if he had any last words. "Let's do it."

When Dan Wieden of Wieden+Kennedy was tapped to create a tagline for Nike a decade later, something about Gilmore's words just seemed to fit. "Let's" was changed to "Just" to add a dash of emphasis.

So who came up with the slogan? 
My guess is the same one that revels in people fighting, stealing and yes killing to get Nike shoes.

See: Sneaker Crimes: 5 people shot for their shoes.