Re: Illustrations for a kids book
Is she self-publishing these books?
It sounds as though she is. Then make sure you charge a fair price, and get paid! You could check the Graphic Artists Guild Handbook: Pricing and Ethical Guidelines, which is a great resource.
If she intends, however, to approach a children's book publisher with everything completed — as a fait accompli — she's not likely to be successful. Editors work with their own illustrators, and like to choose the people whose style they feel would best work with the book (assuming they want to publish the book). Also — there's a lot of competition for alphabet books, and they're less likely to get published. If you and she go ahead with it, make sure she pays you!
(I'm not a children's book author/illustrator, but I took an enlightening and informative workshop on it way back from someone who is, and who was very successful — that's the source of my info.)
Hoping this is helpful,