From the library website choose the tab "Research by Subject." Then click on Art, Architecture, and Design. Navigate to the center of the page to "Core Resources."
Start with Oxford Art Online, an excellent scholarly encyclopedia focused on the arts. Check of the box in the upper right that says "Grove Art Only." Enter the term Marianne Brant and look for the subject entry article. At the end of the article you will usually find a bibliography of additional sources.
Next, go to Art Full Text, also found in the "core resource," and enter the name again.
Try JSTOR and ARTstor as well. ARTstor will give high resolutions of the artist's work. You can download ARTstor images and details of the images and use them for your assignment.
Finally, to find books, go to the library catalog and enter the name of the artist. Click on full record to learn more about whether the book contains a lot or a little about your subject matter.