Zara Tindall was pictured at Cheltenham as fans issued a rallying call for the royal to “support Prince William”. The mother-of-three, 42, is not a working member of the Royal Family, and instead works as a professional equestrian. Zara, who married rugby player Mike Tindall in 2011, stepped out at the Cheltenham Festival on Thursday alongside her husband. This came as several members of the Royal Family have temporarily halted duties, including King Charles, Princess Kate and Prince William. The King and the Princess of Wales are both battling cancer, while William is undertaking a reduced pu…