Watercolour illustrations for a children storybook - 10 illustrations

I am looking for a talented and efficient illustrator who can draw illustrations for children storybooks and is interested in a long-term cooperation. The illustrations need to be suitable for 3+ children.
The job is a part of our educational project addressed to children who speak English as a second language. As a social enterprise we received a grant to develop software and an online platform for language education.
There are 12 short stories, each has 10 A4 illustrations.
We start with one story "My family" - the job is to draw 10 illustrations for the text attached.
We would like the illustrations to be watercolour paintings. We are inspired by Alex Brychta work for Oxford Reading Tree: his visual humour, characters with natural proportions and emotions on their faces. Even if the text is very simple the illustrations complete it and make books attractive for young readers.
Please have a look at these sample e-books:
http://www.oxfordowl.co.uk/EBooks/The%20Toys%20Party/index.html#
http://www.oxfordowl.co.uk/EBooks/The%20Wobbly%20Tooth/index.html#
http://www.oxfordowl.co.uk/EBooks/Top%20Dog/index.html#
What we don't like are flat computer illustrations.

We have already published 6 books and have ready characters for the new series. Please find attaches sample illustrations. We would like the characters to stay as similar as possible. It would be great if you could make the illustrations better:)
We would like to see the line drawing first and then after feedback move to the next step of colouring it with water paints.

The books will be used firstly as e-books in our software and later on printed as separate products. We will distribute them worldwide, but start with the UK nurseries, libraries, and parents. So there is a room for your own promotion and development.

There are 6 characters in the stories: Mum, Dad, brother, sister, grandma and grandpa + two pets - a cat and a parrot. I hope the sample illustrations will help imagine the family.

After accepting that job we will be able to post 11 books for 1100 pounds.