Lady Violet Foyle was the head of the Seamstresses Guild. She was not really a seamstress herself, but it does seem she possesed some fighting ability.
She claimed she serves the Red Queen.
She injured and was injured by Liang, when she tried to kill Liam Aurelius. She is not a friend of Amelia.
Liang eventually killed her when she and others visited the Cethedral.