My suggestion is to think about what you draw best and than create a story that can use this. If you draw cats well than maybe write a story about cats.
Your client is infant to 7 years old. It can be an ABC Book or Counting Book. It can be in another language. It just has to be original and NOT PLAGIARIZED.
Examples from previous classes:
https://mdoportfolio.weebly.com/childrens-book.html
https://gd-worklb.weebly.com/childrens-book.html
https://blade17.weebly.com/bens-balloon-childrens-book.html
https://hlportfolios.weebly.com/childrens-book.html
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The template to use for this is linked here: https://docs.google.com/a/umich.edu/viewer?a=v&pid=sites&srcid=dW1pY2guZWR1fHNreWxpbmVzdGVhbWFydHxneDo0ZmI1ZWNiNWY0ODE1MjJi
But you could draw one out on whatever paper you have.