Question: who plays james corden's sister in gavin and stacey
[{'answer': 'Sheridan Smith', 'provenance': [{'wikipedia_id': '25831483', 'title': 'List of Gavin & Stacey characters', 'start_paragraph_id': 18, 'start_character': 31, 'end_paragraph_id': 18, 'end_character': 45, 'bleu_score': 1.0, 'section': 'Section::::Characters.:Other characters.\n'}]}]