By Mariam Khan A British family holidaying in the sun were left “terrified” after being circled by a shark at a beach in Spain. Holidaymaker Jessica Kenny was paddling in the sea at Playa Arenal d’en Castell, Menorca, with her four-year-old son when she spotted the shark. The 27-year-old realised quickly that the the shark was following her dad, Darren, 57, who was swimming ahead towards some buoys. Passers-by began screaming and calling for the lifeguard, who dialled for backup and put the red flags out. Children were evacuated from the sea, but others were allowed to come close enough to vid…