Hi Denise-
Thanks for reaching out, and thanks for using the Crio WordPress supertheme.
I checked out your site, and it looks like you may have already solved this issue, because I don’t see the white border you’re describing.
Generally speaking, you’ll want to make sure that the section with the image is Full Width. Look for the gray-colored Edit Section menu, and use the Section Width control to toggle between full-width and contained.