She's making a massive strategic and tactical error, on several counts. Firstly, she is pandering to a hard line Brexit group (represented in Parliament by the likes of Redwood, Rees-Mogg and Cash, people who's grip on reality is light) because they have just enough numbers to hold her to ransom. The strategy is therefore an intra party led one, not a real world one. Secondly, I don't believe that these people's hatred of everything the EU stands for and every scrap of its work is actually representative of the majority of Brexit voters, so she is trying to satisfy a minority at the cost of the majority. Thirdly, because she will fail, the negotiation will entail compromise which these people will oppose tooth and nail. Above all she will fail on immigration, the one measurable dear to many Brexiters hearts. Many are expecting not just a complete halt to immigration but the disappearance of 'foreign' kids from classrooms and nurses and doctors from hospitals (whether these foreigners are from the EU or not is immaterial I suspect).
And there is the issue of competence. Apparently she left any mention of Gibraltar out of her Article 50 letter, despite being told that the EU response was likely to include it, precisely to give Spain an 'easy win' and get the discussions off to a good start. Completely underestimated the rabid response here (mainly from her own side) and in Gibraltar. Likewise with her miscalculation with the clumsy threats about security in her letter, which members of her cabinet immediately had to back track on, but not before winding up many across the channel.
I believe in ten years time we will be looking back and lumping together Cameron, who led us into this mess through worrying about his own party, and May, who will **** up the negotiation for precisely the same reason. Two selfish and self centred politicians.
Just my opinion of course.