How many Credit Card complaints did Sharon handle?
Credit Card refers to Product = 'Credit Card'; Sharon refers to server = 'SHARON';
SELECT COUNT(T1.`Complaint ID`) FROM callcenterlogs AS T1 INNER JOIN events AS T2 ON T1.`Complaint ID` = T2.`Complaint ID` WHERE T2.Product = 'Credit card' AND T1.server = 'SHARON'