She wrote in because recently Dr. Phil said on national television and still has it on his web page that obesity is a risk factor for developing rheumatoid arthritis. This is incorrect. Weight is a risk factor for developing osteoarthritis, but not rheumatiod arthritis. These disorders ARE NOT the same.
Her organization is doing a "post your numbers" (or numbers in support of someone else) project Similar to the Facebook "colors" project for breast cancer awareness. They're asking people to post weight/age of onset/current age.