The re-appearance of Sandy, who was cared for by the Scarborough Sea Life Centre back in 2010, is the first time the centre has had photographic proof that one of their pups has both survived and thrived after being released into the wild.
She was spotted with her new pup on the Lincolnshire coast, where she has joined the Donna Nook colony, and identified by a tag on her flipper.
Sandy was taken in by the centre in December 2010, when the distressed newborn was found on the beach in Redcar. She had deep cuts to her flippers and nasty mouth abscesses.
She stayed in Scarborough for two months under the care of supervisor Lyndsey Crawford Darwell to recuperate, and in February 2011 was deemed fit enough to be released further down the coast at Donna Nook.
Lincolnshire Wildlife Trust warden Lizzie Lemon spotted the distinctive blue ID tag - and the number 92 - when she photographed the mum and her offspring on the shore this month.
“We have rescued and released hundreds of sickly, injured or orphaned seal pups,“ said Lyndsey.
“The ID tags we fit them with are only visible when they are out of the water and it is rare they allow anyone close enough to read them.
“So although there’s evidence to suggest most of the pups we release go on to resume the normal lives of wild seals, this is the first categoric proof of one of our rescued pups going on to have a pup of her own.
“Lizzie’s pictures gave all of us a real warm glow. They were the perfect Christmas present for the whole team.”
Over 1,900 seal pups were born at the protected reserve in Lincolnshire this season.