You can change the approach like -

1. Create separate Member ID as Primary Key instead of using the member_name as the foreign key. You can create a unique numeric member_id as the primary key in the member_profile table and This member_id will be referenced as a foreign key in other tables.
2. Create unique constraint on member_name in the member_profile table so that duplicate entries are prevented.
3. Use member_id as a foreign key in each of the related tables instead of member_name.