show info for all females (sex is F).
select * from people where sex = 'F'
who are candidates among them? Just show their names.
select t1.name from people as t1 join candidate as t2 on t1.people_id = t2.people_id where t1.sex = 'F'
list the result in the alphabetical order.
select t1.name from people as t1 join candidate as t2 on t1.people_id = t2.people_id where t1.sex = 'F' order by t1.name