I have posted my opinion that JRRT was a bit over the top in his earlier phases - BoLT, mainly - in making his baddies, mostly
Melkor (but also
Ungoliant, and there were these Loki-like Valinoreans early on), rather over-powerful; and that as shown in "Myths Transformed" in HoMe volume 10 "
Morgoth's Ring", he was straying in the same excessive territory (and never mind his "
Mannish tradition" delusion, which simply doesn't work with
Bilbo's,
Frodo's and
Sam's "Red Book of Westmarch"). What I have called, perhaps heretically, his Peter Jackson prefiguration.
BoLT was
the young JRRT. The writings from "Morgoth's Ring" on were the ageing, exhausted (by the singular effort of writing his masterpiece, LoTR) JRRT. He spent his best years writing "The
Hobbit" and "
The Lord of the Rings". He would have wished, apparently, to have spent them to continue writing "
The Silmarillion". We can all be thankful he didn't.
Now details about this may be in parts if HoMe that I simply haven't memorized. But I remember an early version of the death of Huor,
Tuor's father, of having him slaughtering
Balrogs with his fearsome
axe. And in an early version of "The
Fall of Gondolin", where among those slaughtered by some Elven troops is said "and they were Balrogs" (later changed to "and there were Balrogs"). What I don't know is from what phases of his father's writings Christopher had to glean this whole Ungoliant business. My guess goes to the early, über-monster phase of JRRT's writing. How should this Ungoliant have ever mated with anything to produce, after a long lineage,
Shelob? Who was sent packing (with not a little of her own doing) by the Hobbit Sam? I mean even in the real world, lots of spider males are the after-sex snack of their mates. I don't see Ungoliant even waiting this long, she would just gobble up anything without waiting for "entertainment". But how do these early-phase Balrogs (hardly better than the later
Uruk-hai), no matter how many of them, manage to drive off Ungoliant? She would have munched them like popcorn. JRRT (much?) later seriously uprated the Balrogs in saying that there had only ever been seven of them; but is this ridiculous Ungoliant scene concurrent with the seven-Balrog phase? And the bit about the rumor of her going off south and then devouring herself - again not a good writing day for JRRT when he wrote that, not at all.
I mentioned
Yavanna as creator of the
trees in my short, rather brusque post of just past midnight today my time above. Yes, Ungoliant grew stronger as she consumed the sap (light) of the trees - one after another. (This concept of Ungoliant getting stronger no matter what she does - I'm sorry (actually not), I can only describe that as brain-dead!) Mingling the light, as was done in
the Silmarils, could very well have increased the potency by several orders of magnitude. By the way,
Varda had nothing to do with the creation of the Two Trees. She rather took silver dews from the vats of Telperion, and made new and brighter stars [for the soon-to-awaken Elves]. Who was involved was
Nienna, one of the three great Valier.
Fëanor was Valar-like in the creation of the casings for the Silmarils. And Varda hallowed them. I see them, and will not change my mind, as being deadly to all
evil things. Including Ungoliant.