Unless she is selling her own fonts on this website, I think you both could work more on CSS embedding (yeah, I read this is not an option for you now, but I insist).
If the case is a heavier graphic work upon fonts (gradient colors, twisted alignment, glossing, embossing, engraving...), making it really impossible to render thorugh CSS options as she needs, then I would recommend doing the following:
use images through CSS (perhaps a sprite), and hide the anchor text with text-ident.
html
<a href="work1.html" title="My first work" id="firstWork">My first work</a>
css
#firstWork {display: block; width: 200px; height: 150px; background-image:url('img/firstwork.jpg'); text-ident: -999em;}
This is one technique. Yeah, I know, Google can punish that, but you know, I never heard about one single site penalized by using this.
Another way would be using img tag inside anchor tag ALONG with text, and then using CSS to hide text and correct positioning img if needed. This last option gives your the possibility to add alt, title, longdesc to image, increasing the information quantity and quality being indexed.
You can even go further with this last option and go for a even better and fresh solution: using figure tag, available for HTML5, along with figcaption. The idea is keep anchor->figure->img+figcaption.
Figcaption would make the anchor text role and you can use CSS to hide it.
Well, 3 solutions. Pick one. I'd go with the last.