I just heard from a very reputable inside source at CBS that Charla and Mirna have indeed won the Amazing Race All-Stars.
The race apparently came down to a challenge at the San Francisco Botanical Gardens where the cousins, up against Uchenna and Joyce, compete to identify and sort a series of plants and flowers. The teams are neck-and-neck, when a bad detour choice requires Joyce to shave her head once again. She refuses, and Charla and Mirna breeze past to the finish line and win the million dollars.