State number of legislators who are not the senator among female legislators.
not the senator refers to class IS NULL OR class = ''; female refers to gender_bio = 'F';
SELECT COUNT(*) FROM current AS T1 INNER JOIN `current-terms` AS T2 ON T1.bioguide_id = T2.bioguide WHERE T1.gender_bio = 'F' AND (T2.class IS NULL OR T2.class = '')