A woman has been found guilty of fatally stabbing her film director sister in the neck before making off with her diamond-encrusted gold Rolex watch. Nancy Pexton, 70, was convicted by an Old Bailey jury on Wednesday of the brutal murder of her film director sister, Jennifer Abbott, 69. She fatally stabbed Ms Abbott ten times, stealing a diamond-encrusted gold Rolex watch from her Camden, north London flat. Ms Abbott, a US citizen, was last seen alive at 7.36am on 10 June last year, returning from walking her corgi, Prince. Pexton contacted her at 11.36am, then travelled to the Mornington Place flat, arriving at 12.45pm and leaving an hour later. Ms Abbott’s body lay undiscovered for three days until 13 June, when a concerned neighbour, noticing the dog's unusual silence, forced entry with a scaffolding pole. Her niece, Mai Pexton, was seen banging on the door. Following the killing, Pexton reported an overdose to her GP and was hospitalised until her arrest on 18 June.…