Ive thought about it, and I have concluded Mab has become more.
she is now Mrs. Dresden.
It is more like Harry is now Mr. Winter rather than the other way around.
About Mab's soul. Mab spends time with Sarrissa like a few hours a year? And I suspect she did that to make sure that there is backup for WL position if it is nessasary. That is not enough to rekindle a soul like Mab. Mab's interactions with Harry is not long enough or intense enough to rekindle Mab's soul either.
It is possible that these interactions helps in slowing down the total subversion of Mab's mortal soul. What we saw in CD, if it is a spark of Mab's soul at all, is just what is left. To expect that prolong interactions with Harry and other mortals will eventually rekindle Mab's soul in just a few decades is extremely unlikely. Given enough time and nurture perhaps, like a thousand years of constant effort, maybe it is possible, but in just a century or two? and only a few hours a year? Not likely. And Mab herself will have to want it, which I don't think is the case. She seems to be content enough.
Changes did come to immortals, like what Mother summer said. But for immortals, those changes happens in hundreds, even thousands of years, if it ever happened at all and the immortal is certainly going to react badly to it.
We shall see if this is even possible. If Harry is able to do the same thing to the Winter knight mantle as what he did to laschiel's shadow, than we will know for sure that changing an immortal by prolong exposure to mortals is possible.