Linda used to be a Quaker (a member of a religious Christian movement). She now helps Arthur with his sobriety in his life, among other things.
Series 3 Edit
Linda attends the wedding of Thomas Shelby and Grace Burgess, and helps Arthur with his best man speech for the wedding. She proves to have a fairly large influence on Arthur, a quality that Thomas has taken to disliking.
She tries to get Arthur to stop 'work' at night for religious reasons, which Arthur does not fully oblige but is seen to compromise, for example after burning a pub for the Blighters he immediately goes home despite John's mockery of him.
Furthering her insistence that Arthur's night work should end, she announces to him that she is pregnant.