I am not a Conservative (big C) in my politics nor thinking but I truly believe, if we put party politics aside, she is the right person for the job, out of the available candidates.
She is a conviction politician who hasn't played the "old boys network" card, mostly because she didn't have one to play. She's arrived to her position through being a great, but not perfect, politician, who works harder than most others.
That isn't to say I agree with all her views as Home Secretary. The RIP Act -
https://en.wikipedia.org/wiki/Regulation_of_Investigatory_Powers_Act_2000 and later versions that sh's still trying to push through are draconian and wrong but...... I believe she is doing so for the betterment of security for the UK, rather than some other reasons or personal goals.
I will say that we're in unprecedented times politically - Leaving the EU, an opposition in disarray, the GBP£ a shadow of it's former self and pretty much no money in the piggy bank.... Hard times indeed with an even tougher job ahead of her.