Witnesses claim that an onlooker tackled a man with a gun and wrestled him to the floor, before a gun shot was fired.
One witness claimed the gunman looked to be in his 60s or 70s.
Eyewitness Clarke Rothwell, who runs a cafe nearby said: “Three times she was shot, the initial time which then she dropped to the floor, and two more times.
“The third time he got close proximity, he shot her round the head area.
“In the meantime he was stabbing her as well, he was stabbing her with his knife.”
Mr Rothwell said there was blood everywhere at the scene.
One witness said: “The whole scene has been taped off. There are armed police everywhere.”
Graeme Howard, 38, who lives nearby said: “He was pinned down by two police officers and she was taken away in an ambulance.”