Hello! Congratulations on finishing the manuscript for your children's book. I consider myself a cartoonist first and foremost, and I actually have prior experience illustrating a children's book for an Australian client. I believe we'd work well together.
I estimate it will take me 14 days to complete your 12 illustrations, if you only require a simple background. It might take me longer depending on the complexity of your illustrations, but this will be definitely be discussed beforehand, so there'll be no surprises.
You can take a look at my Freelancer profile for some examples of my style and prior work. If you have any questions, or would like to discuss your project further, please feel free to send me a message and I'll respond ASAP.
Thank you for your time, and good luck!