Who is Maud Allan from The Eye in the Door and what is their importance?

Maud Allan (1873 - 1956) was a Canadian-born dancer and performer. Allan is mentioned in the narrative in reference to a libel suit she filed against MP (Member of Parliament) Noel Pemberton Billing sometime before the end of WWI. The Author's Note which follows The Eye in the Door gives details of the trial and the events leading up to it.