Oh, Lea is definitely stronger than the Ladies. It's mentioned several times, and also look at her performance in Changes (she kills
two Lords of Outer Night with one spell, though admittedly by surprise -- and gives Harry and Susan
really powerful magical items) versus the frankly pathetic performance the Faerie Ladies have demonstrated on-page... we see 3 of them die, 2 to massively inferior opponents (Aurora to Harry + pixies, Maeve to Murphy). Sure, Maeve was on Halloween, but Lea would just have shielded herself or dodged the bullet or frozen Murphy in ice or something... she's confident enough in her ability to defend herself that she lets Molly try to stab her with iron in "Bombshells" and casually blocks it (and she's
not immortal... she specifically says that Molly would have killed her...)
Lily does some pretty impressive stuff, admittedly, but it's really not THAT much beyond what we've seen Harry do ... her wave-of-fire spell in CD probably involves a lot less energy than Harry's Winter Knight freeze-the-lake effect in CD, and likely is comparable to Harry's lake-freezing "twenty-story column of fire hot enough to vaporize ten-gauge steel" all the way back in WN, which is just him moving energy around with standard wizard magic, no Winter or Hell/Soulfire or other boosts involved. Her follow-up sun-ball spell is pretty impressive, admittedly, but it seems like a faster-cast version of Harry's "little ball of sunshine", not something on a whole different level... And more importantly, Harry is totally without gear and running out of energy in that fight. If Harry had been anywhere near full power, he'd have taken Lily down before she ever got a chance to put together the sun-ball spell; just blocked the wave-of-fire and then struck back.
yeah it is curious how it's worded. Maybe because the Mothers are more limited in what they are allowed to do vs what Mab is allowed to do? The Mothers are so weighed down by their sheer power they are more like forces of nature than people who can take action.
I think the Mothers are kind of... outside everything else. There's a WOJ that the Erlking is Wyldfae, not subject to Mab or Titania, but he has "origins in the Summer-side of the cycle of seasons" and is beholden to Mother Summer (but pretty much everything in Faerie is...)
I'm not sure they are even Fae in the strict sense, Mother Winter has iron teeth after all.
I also wondered if Mab’s reference to “her Winter” memt that their were sub courts to the full Winter Court?
Possibly it's excluding beings like Kringle and any other Winter-affiliated or Winter-leaning Wyldfae.