She is so obviously out of her depth, I can see a situation, where she is unable to carry on, due to health concerns.
The fact she has disappeared for 4 days and then comes out seemingly completely unprepared for entry level questions, must be alarming for her aides and supporters.
She will have been focussed on preparing for next week's party conference. Just to manage expectations here, I don't anticipate this will be reflected in the quality of the speeches, but I am sure she will have paid more attention to her wardrobe than her predecessor, Jog on Johnson in his white shirt and work shoes.