Question: who plays the voice of mabel in gravity falls
[{'answer': 'Schaal', 'provenance': [{'wikipedia_id': '7297505', 'title': 'Kristen Schaal', 'start_paragraph_id': 0, 'start_character': 8, 'end_paragraph_id': 0, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '7297505', 'title': 'Kristen Schaal', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 1411, 'bleu_score': 0.8623875421672701, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8692612249743176509}, 'section': 'Section::::Career.:Film, TV and radio.\n'}]}]