Lawfully represented by member and friend (7)
I believe the answer is:
Here is my best explanation:
'lawfully' is the definition.
('legally' can be a synonym of 'lawfully')
'member and friend' is the subsidiary indication.
'member' becomes 'leg' (leg is a kind of member**).
'and' says to put letters next to each other.
'friend' becomes 'ally' ('ally' can be a synonym of 'friend').
'represented by' is the link.
(Other definitions for legally that I've seen before include "In a manner approved by law", "As regards the law", "Licitly" and "Lawfully".)