Illustrate one or more pages of my Christian children's book

Hello! My name is Jennifer, and I have written a Christian Children's Rhyming book about the effects of emotional abuse and how that impacts our ability to love ourselves, as well as our physical health. I have an image in mind for the lead character in my book, Jasmine! Jasmine has tan skin, and curly, big, layered hair. She is beautiful and smiling. I would like for her to be Puerto Rican. She is an "exotic flower" living in a big city and wears extremely bright and colorful clothing. She is bullied and emotionally abused by those around her. This causes her beautiful bright colors and tan complexion to fade to grey, and for her to become very ill. When she is near death, she fights for her life. She prays; asking God, and neighbors for help. She learns that God loves her for who she is, and she learns to love herself too. She also discovers that she is never alone because Jesus is always with her. For the cover, I need Jasmine, about 8 years old. She is standing front and center on a crack in the sidewalk cement. She is the "exotic flower" that grows from the crack in the cement. Behind her are buildings on either side of her. In between the buildings, arching across the sky is a beautiful rainbow. She is wearing a brightly colored dress. I don't want this to look "cartoonish" as this book deals with very real and serious topics. I want her to look beautiful. I have a very small, Christian publishing company who is interested in seeing an illustration of the book. Ultimately, it would be my burden to get the entire book illustrated. I was told that I could wait to do that until I have a contract in hand. The cost of everything will determine whether I just get the cover of the book illustrated or the entire book now. I am recovering from being sick with cancer for a few years, so I have not worked in a long while. Please keep this in mind if you choose to submit an answer to this lead, as I don't have a lot of funds to work with. Please let me know how much it would be for just the cover, and how much it would be for 20 illustrations. I would need at least an illustration for my cover ASAP. Thank you so much and I look forward to your response! God Bless you all! :)