One of the ways Jim loves to hide things is by showing us the effect and then explaining the cause in an urelated fashion later.

So, at the beginning of Battle Ground, Molly disappears from the docks in a blast of cold air. The Winter Knight feels the cold. Major forces were being thrown around.

Later, Marcshiel teleports during the fight with Ethniu near the lake. Harry is gobsmacked and goes into a long monologue about how awesome this is and how much skill it takes, even when both points are within easy viewing distances.

The thing is, if Molly had opened a way to the Never Never, it would have been visible and Harry's seen plenty of those. But because he didn't see her disappear here and reappear there, he never put two and two together to realize that it was a teleport. (Our hero is not all that bright.)

Is this a clue that Molly is as far above Marcshiel as Marcshiel is above Harry?

Harry cut off all other prisoners not in the same confinement mode from communicating with Thomas. There's only one prisoner before Thomas in 'contemplation' mode. The British guy.

Mab chose Molly.

In the grip of insomnia last night I went back and re-read the chapter in Peace Talks where Harry summons Molly and this bit jumped out at me. It was easy to miss given all the bombshells with the summoning and Molly's tenuous mortal status.

…Molly probably wasn’t going to forgive herself for assisting in what had amounted to a very complicated near suicide. There’d been a lot of fallout, on every conceivable scale. Very little of it had been Molly’s fault, directly or otherwise, but she’d been a mover on that scene, and she probably felt at least as bad as I did about it, and I’d been way more in the middle of things.

And, being a wizard, I felt guilty as hell for walking her into that. I hadn’t had much choice, if I wanted to save my daughter’s life, but thought the cost was worthy, it still had to be paid-and Molly had laid down cold, hard cash.

So cold and so hard that Mab had wound up choosing her to be the new Winter Lady, in fact.

Suddenly I wondered if maybe I hadn’t been hard enough on myself. I mean, hell, at least when I’d become the Winter Knight, I’d made a choice. My back had been to a wall and my options had all sucked, but I’d at least sought out my bargain with Mab.

Molly hadn’t been consulted, and Mab’s policy on dissenting opinion was crystalline: Deal with it or die.

Of course, inveterate dissenters like myself, it created a pretty simple counterpolicy for when I was tired of Mab’s crap: Deal with it or kill me. Mab was a lot of things, but irrational wasn’t one of them, and as long as it was easier to put up with me than replace me, we had attained a state of balance. I imagined that Molly had come to similar arrangements…

There’s so much to unpack here. But, first and foremost, MAB CHOSE MOLLY TO BE THE WINTER LADY.

Which means everything we’ve been told or shown regarding succession of the lady mantles is either wrong, incomplete, or the person telling us how it works has been lied to. Unreliable narrators is the rule instead of the exception in DF. Fae are information hoarders. People wearing fae mantles must behave as fae would, so they are obligated to hoard information and not release it unless you back them into a corner and ask them three times. They get a bit testy about that.

Now, that opens the door that Titania may have chosen Lily to be the first replacement Summer Lady. If the queen gets to choose from available vessels for fae power, Sarissa being chosen as the Summer Lady can only be viewed as revenge for Aurora’s death. After all, Mab did choose the person who caused Aurora’s death as her Winter Knight.

So, perhaps in a way, Molly brought herself to Mab’s attention by helping Harry arrange his death? Lea instructing her during her year as the Ragged Lady might have helped prepare her to be a vessel for fae power, but I think she was already on the board. Besides, due to Lea’s obligation, she would have been bound to instruct Molly. Molly made a cold, hard decision, against her emotional human interests, to help Harry suicide. That really does ring of Winter.

Mab could have chosen Murphy for the mantle. There’s no age requirement that we know of. Molly may have been technically virginal, but Lily certainly wasn’t since Slate had raped her. Murphy wasn’t a virgin, but she had never had a child, so she would have technically been allowable by the flawed rules we have been shown.

And let’s face it, veiled or not, there’s no way an apprentice wizard’s veils would have been good enough to conceal her from Mab, who in terms of age, experience, power and sneakiness is leagues above Molly in Cold Days.

So, when Maeve died, Mab had a choice and she chose Molly.

Mind. Blown.

Margaret (Maggie) Dresden, Margaret (Molly) Carpenter, Margaret Dresden (LeFay). Maiden, Mother, Crone?

IMHO, the nicknames are to distract you from the fact that the most important women in Harry's life are all named Margaret.

In fact, since Madge if a diminutive form of Margaret, I'd be completely unsurprised if Mab's proper name wasn't Margaret.

At the end of BG, Harry goes with Molly to the Carpenter's house for Sunday dinner. When Michael drops the bomb that he knows she's the Winter Lady, he then expands on the preparation they've done to get ready for Molly to come over. They've broken out her Grandmother's silverware.

In Fool Moon, Bob is explaining about different kinds of werewolves. Loup Garou are cursed to be consumed by a wild spirit. But it's not a run of the mill curse. You've got to be really powerful. A major sorcerer, a demon lord or a faerie queen. And, the only way to stop them is with inherited silver.

Do we know a faerie queen with inherited silver? Why, yes. Yes we do.

Man, listening to the audio book of Battle Ground and different stuff is sticking out that I just zoomed past while reading.
Here's another. It really stuck out at me in the audio book, but I zoomed past it reading.

“We have to answer for this,” I said quietly. “We have to help. The wounded.” I didn’t look back at the dark opening in the base of the Bean. “The dead. We owe them. You know I’m right.”
“That could be a tough sell,” she said in quiet answer.
“I’m not asking,” I said. “My fealty is a two-way street. I have gone above and beyond my duty to Winter, right in front of God and everybody, by doing what no one else could. Now Winter will respond in kind, by helping as no one else can. You will help them. Every one of them. Do it in secret, no connections. We’ve interfered in their lives enough. This will happen.”
The Winter Lady gave me a very long, very intent stare.
And then she shivered and bowed her head.
“Already you have bound a Titan. And now a Queen. Sometimes,” Molly whispered, “I’m very proud to be your friend, Harry. And sometimes you frighten me.”
Sometimes I frightened the Winter Lady. I shook my head.

The fae CAN'T leave a debt unsettled. Just like Mab had to repay Waldo for removing the rebar from her neck, even if it is held against her as a favor, the debt has to be acknowledged and balanced.

When Harry said he went above and beyond his duties as the Winter Knight, he wasn't exaggerating. Harry Dresden couldn't bind a titan. The Winter Knight couldn't bind a titan. The Warden of Demonreach can and did.

Winter has no hold on the Warden of Demonreach.

Winter owes the Warden for binding Ethniu, in support of the accords, and Harry collected. Molly has no choice in paying for the injured and the dead. Just as she has no choice in collecting on the favor Harry owes her for making the glamour he used to evade Eb.

Which puts a different spin on Molly presenting the envelope to Harry on Christmas Eve at the Carpenters. She's not giving a gift, she's settling a debt. Which clearly underlines Harry as an unreliable narrator.

Which, in turn, expands on the unease Molly felt when she left the house in The Good People. She isn't human any longer, and she thinks Harry knows it. She thinks Harry is the same as she is because he so casually bound her with fae logic and Winter's debt to the Warden of Demonreach.

Subject says it all. Has Harry lied since he accepted the mantle? And I mean that in the fae way. Has he told an outright mistruth. Not from a certain point of view. Not a lie of omission. Not agreeing with someone's misstatement or misperception. And outright mistruth?

The fae can't lie, but has Mab incorporated not lying into Winter Law? Since at least two of her vassals are mortal and have free will, and Maeve was Nfected and could lie despite possibly being fae.