The letter is Q

Robert Pyle to Anh Quach
Hong Quach to Edlow Quarles
George Quarles to Sylvia Queen
T Queen to David Quigley
Dawn Quigley to C Quillen
Carol Quillen to R Quillen
Rachael Quillen to P Quinlan
Patrick Quinlan to John Quinn
Joseph Quinn to T Quinn
Terry Quinn to Thomas Quirk