She is utterly awful, and her track record is pretty dire - the go home vans, Windrush, telling the Police Federation to stop crying wolf and so on.
Her handling of Brexit has been terrible as well - Brexit means Brexit, red, white and blue Brexit, calling the early election and and all that has been awful.
However, I think any PM would be in a difficult situation with regards to Brexit, and there is only one deal to negotiate from the EU. That's not her fault.
The ERG (along with all of the other Brexiters in Parliament - just look at David Davis and Raab) are useless and have at no point been able to provide a viable plan for Brexit, so what they are doing is only destabilising the country even further. A no deal Brexit would be absolutely disastrous for the country.
She has been put in a difficult situation, and she has tried her best - the deal isn't that bad, but everything else she has done is so utterly crap that she does not deserve anyone feeling sorry for her.
She, must like most of the members of Parliament, are only interested in their careers, their own bank accounts and they do not care one bit to focus on the betterment of the country and the people of this country.