A woman who murdered her sister in her London flat and stole her Rolex watch has been jailed for life with a minimum term of 22 years. Nancy Pexton stabbed Jennifer Abbott 10 times and left her body for three days in the property in Camden, a court heard. On Wednesday an Old Bailey jury convicted Pexton , 70, of murdering Abbott, a film director, on 10 June last year. Sentencing Pexton on Friday, Judge Anuja Dhir said she was sure Pexton had intended to kill her sister, given the “ferocity” of the attack. She said: “Your actions and conduct after the killing demonstrates not only your absence of remorse but also a deliberate and callous attitude towards what you had done.” The judge said taping up her sister’s mouth was a “deliberate act of degradation” which was “callous, demeaning and cruel”. She added: “This act demonstrates the depth of your animosity and hostility towards your sister.…