That turned into a personal catastrophe for May. She went to meet the leaders hoping that her plan would move things forward, and she could then go to conference saying that she had success, and see what having strong and stable leadership produces. It is beyond me why she goes on digging herself into even deeper holes. So now we are told that a new plan will be produced. I am not sure how much longer the EU can continue to prop her up, but should she fail at conference then the calls for her to go will increase. The problem with that is that the UK would need extra time to go through a leadership election, and would have to request the EU to extend the Article 50 talks. It would be quicker to rescind the laws passed on the March deadline, it could be done in one day, than it would for the Tories to organise their election with the various stages that it must go through.
May was warned her 'Robbins' proposal was unacceptable to all. Even Barnier prefers a Canada style deal that requires the addition of services to benefit all. This would maintain all of the red lines May originally started with.