Like many celebrities, Jessica Simpson does take advantage of her celebrity status to help non-profit organizations gain more visibility and raise more money. I believe that the organization you're talking about is called Operation Smile and its stated mission is:

"Throughout the world, Operation Smile volunteers repair childhood facial deformities while building public and private partnerships that advocate for sustainable healthcare systems for children and families. Together, we create smiles, change lives, heal humanity."

Popular actress Roma Downey is also involved with Operation Smile (she's best known for her role on Touched by an Angel from a few years ago, if, like me, you haven't heard of her), but Jessica Simpson is the primary spokesperson for Operation Smile, and with her work as a pop singer, actress, company spokesperson, and clothing designer, I just wonder how Jessica has time to be involved in any charity work, let alone her work for Operation Smile.

Nonetheless, she does find the time and it's good work for an organization that is doing good works throughout the world.

In terms of getting in touch with Operation Smile, I believe that your best bet is to contact the organization through the Web site, if you can. You could try contacting Ms. Simpson, but I somehow imagine that it would be intercepted by her publicity team / publicist and be forwarded along to Operation Smile regardless.

Good luck to you with this quest and Godspeed with your surgery.