Murder in the Kitchen

Well, as you can see (probably not) from the picture below, the gas jets on the stove are open. Both doors are locked from the inside - how could a murdered have escaped? Miss Robin Barnes, the victim, was involved in number of domestic tasks in various stages of completion. This can be interpreted several ways. Several unfinished tasks with only the cake being complete. She seemed to be upset and unable to concentrate so she committed suicide. Or, the tasks were in the normal scope of being a housewife. it is suspicious that Robin decided to commit suicide int he middles of making dinner - suicide is not an impulsive decisions. Furthermore, why would she cook dinner if she was on the brink of suicide?
The table and tablecloth are askew in an otherwise harmonious kitchen. Knife: (on the chair), was presumably used to stuff newspaper around the door to prevent any carbon monoxide from escaping.
There is a drink at the table - had she had company? the can would be swabbed for DNA. The ice tray on the floor adjacent to her body may indicate she had been getting ice for the visitor.
The rosy hue of the body indicates carbon monoxide - murder.