Choices

[Mira]

You forget:  Michael has some extra guidance! 
Without Harry's assistance, SI & Murphy will have needed some extra help... help that Michael is well-situated to provide!  Obviously, that's no guarantee Jim will have written it that way; but it'd be  a nice exemplar of God's Providence, with Michael's multiversal presence situated to support Murphy (or in a different Alt!Universe, Morty?) when that alt!Harry does not.

Unless Murphy is closed minded about the supernatural, there is no guarantee that she'd be receptive to a so called "Holy Knight."

I don't see any way for Mirror!Murphy to have buried her head in the sand and deny the supernatural; and Harry will *very* much be on Mirror!Murphy's radar -- as a Bad Guy(tm)!

Actually you make my point very well.. Murphy sees things in black and white, if all she sees is an "evil Harry" how do you think she will see the supernatural in general?  Also remember how quickly she was to jump to conclusions in the first couple of books because she did not understand Harry's world at all.

[g33k]

... there is no guarantee that she'd be receptive to a so called "Holy Knight."

Michael doesn't often introduce himself as a "Holy Knight," though:  he just steps up to help.
And Murphy actually has amazingly-good "people-sense."
It'd make good sense in both Doylist & Watsonian terms.

If Michael is guided to aid her in time of need -- and I allege that (in an Evil!Harry universe) this is likely to happen -- Murphy will take the help, and (cautiously) begin trusting Michael, as he becomes a good source of supernatural intel & an ally in protecting Chicago.

[Mira]

Michael doesn't often introduce himself as a "Holy Knight," though:  he just steps up to help.
And Murphy actually has amazingly-good "people-sense."
It'd make good sense in both Doylist & Watsonian terms.

If Michael is guided to aid her in time of need -- and I allege that (in an Evil!Harry universe) this is likely to happen -- Murphy will take the help, and (cautiously) begin trusting Michael, as he becomes a good source of supernatural intel & an ally in protecting Chicago.

Will she?  Or will she take the attitude that whatever it is, it is a law enforcement issue so some civilian carpenter can butt out? 

[g33k]

Will she?  Or will she take the attitude that whatever it is, it is a law enforcement issue so some civilian carpenter can butt out?
 

Remember:  at the point of divergence, it's the exact same Murphy, with the exact same attitudes.  So yes, there may be some suspicion/distrust, just as she wasn't yet to the point of trusting Harry.  Also remember:  Murphy doesn't need to "call Michael for help" in order for Michael to show up via his own guidance.

But she'll be just as in-need of assistance from Michael as she was from Harry.  How many times will Michael need to selflessly risk himself to pull her (and other SI) out of danger, before she trusts him ... at least a little bit?

Michael's fundamental goodness is something that will speak to Murphy; and his free and ready faith (which Harry *never* displays) will do so too.

= = =

In the end, of course, it will depend 100% on how Jim writes it; the whole point may be moot; maybe one or both of them die in the stories between GP & MM...