A while back I was researching fairy tale illustration and one artist I got to know this way and whose art stood out was Nancy E. Burkert.
From "Acknowledgments," by H. Nichols B. Clark:
"Because Nancy Ekholm Burkert's work is so thoughtful and deliberate, she is not a prolific artist. Whether creating an easel painting, a print, or an illustration for a book, Nancy brings to her task the highest aesthetic measure. No detail is too insignificant to warrant intense scrutiny, and her exacting standards reflect the meticulous research she brings to any endeavor. One need only survey the research materials and preliminary drawings she assembled in producing Valentine & Orson to fully appreciate the methodical regimen to which she adheres. As Jane Curley points out in her thoughtful essay, Nancy scours the full spectrum of art history to infuse the requisite image with the appropriate resonance."
Sadly I douldn't find a lot by her on the web. Her work for Snow White looks so well-researched though, delicate and gentle, the colouring reminding me of theso-called primitivists up to Boticelli.
Wikipedia has a list of the books she illustrated and I've found something about her here. (It's a pity there are no pictures to go with that article.) I'm happy some books about her are available.