I agree that given her history it took great courage to take that step. She was potentially putting herself in the cross hairs of the person she was asking to fix the situation. However, what exactly did she bring to Harry's attention? Did she tell him that her husband is creating drugs, participating in black magic, and killing people? She deserves credit for going to Harry, but that doesn't change the fact that she did not tell him the whole story and in a sense mislead him to what the problem was. She told him her husband was missing (true from a certain point of view), but was hoping to put the wizard on a collision course with the Three Eye Operation in order to shut it down. Had she told him more of the truth he might have been better prepared to resolve the situation without it getting as messy. Heck he could have kicked up to the Wardens who would have been all too happy to go medieval on that operation.
Not that simple, when it comes to an abused woman, a terrified abused woman. A conflicted woman, who in spite of everything still loved or thought she loved her husband, dealing with the reality of what he had become. Monica couldn't get away from him, when her sister stood up for her telling Victor to let her go, he killed her. No, Monica wasn't capable of logically thinking it through like you describe, nor culpable. She went to Harry because she knew enough to know the police would merely think her insane.. She was terrified for her kids, as Harry said;
Where she was, there was nothing but an endless, hopeless darkness full of fear, pain, and defeat.
That's what he saw in the soul gaze, that's why he was so gentle with her.
Putting aside Monica's background for a second, trying to do the right thing later does not erase moral culpability from earlier actions. If I and a partner rob and kill someone together and then I later go to the cops to turn myself in and give them information to catch my partner, it doesn't change what I had done. It doesn't paint my actions in a different moral light.
However Monica's background cannot be put aside, it is part of the picture.. If your partner bullied you, if you had no self esteem to begin with because you had been bullied all of your life, if you loved your partner in spite of everything, you might go along.. Does it change the fact that you helped? No, but neither are you totally responsible for your actions. When someone's mind has been so screwed with you cannot judge that their thinking was rational, it wasn't.. To be morally responsible I believe you also have to be able to think rationally, Monica wasn't.
Does Monica deserve grace for her situation? Yes. Does Monica deserve credit for reaching out for help despite her situation? Yes. Does she bear some moral culpability for joining the activities in the first place, not reaching out for help sooner, and misleading Dresden when she reached out for help? I would argue yes, but as I said in an earlier post, that goes not equate to punishment. No reasonable jury is going to lay the hammer down on her.
Because she wasn't morally culpable, her problems started long before she met Victor.