Database: student_club
Question: Among the students from the Student_Club who attended the event "Women's Soccer", how many of them want a T-shirt that's in medium size?
SQL: SELECT COUNT(T1.event_id) FROM event AS T1 INNER JOIN attendance AS T2 ON T1.event_id = T2.link_to_event INNER JOIN member AS T3 ON T2.link_to_member = T3.member_id WHERE T1.event_name = 'Women''s Soccer' AND T3.t_shirt_size = 'Medium'