How many times has Venus Williams won singles at Wimbledon?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'INTERNAL', 'name_': 'Q30', 'id': 0, 'label': 'United States of America'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q41520', 'id': 1, 'label': 'Wimbledon Championships'}, {'type': 'INTERNAL', 'name_': 'Q11459', 'id': 2, 'label': 'Serena Williams'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q11578', 'id': 3, 'label': 'Venus Williams'}, {'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q6023582', 'id': 4, 'label': 'Indiana University East'}, {'type': 'INTERNAL', 'name_': 'Q3037156', 'id': 5, 'label': 'Dorothy Andrus'}], 'links': [{'name_': 'P17', 'source': 0, 'target': 0, 'label': 'country'}, {'name_': 'P27', 'source': 2, 'target': 0, 'label': 'country of citizenship'}, {'name_': 'P3373', 'source': 2, 'target': 3, 'label': 'sibling'}, {'name_': 'P17', 'source': 4, 'target': 0, 'label': 'country'}, {'name_': 'P27', 'source': 5, 'target': 0, 'label': 'country of citizenship'}, {'name_': 'P1344', 'source': 5, 'target': 1, 'label': 'participant in'}]}