> All children of Feanor (the main contingent of the Noldor)
This makes it sound like most Noldor were children of Feanor or that most of them followed Feanor and his sons, but that's not the case. The sons of Feanor and their followers were first to Middle-Earth - is that what you mean by 'main'? It's stated a few times that there weren't as many of them. The Noldor were an entire people, and most were neither Feanor's children nor followers of his children. (They were technically all under Feanor as high king of the Noldor for a time, though.) This is from the Silmarillion, describing their travel through Valinor on the way to Middle-Earth:
> Fëanor and his following were in the van, but the greater host
came behind under Fingolfin; and he marched against his wisdom, because
Fingon his son so urged him
and then after those who didn't follow Feanor cross to Middle-Earth in the north, many die, but there are still more of them:
> for the agony of those that endured the crossing of the Ice had been
great, and Fingolfin held the sons the accomplices of their father. Then there was
peril of strife between the hosts; but grievous as were their losses upon the road,
the people of Fingolfin and of Finrod son of Finarfin were still more numerous
than the followers of Fëanor,
Yes, Galadriel's father, Finarfin, was of the Noldor, and he married Earwen of Alqualonde, the daughter of Olwe, who was one of the two leaders of the Teleri.
All children of Feanor (the main contingent of the Noldor) are dead by the end if the first age).
The few Noldor that outranked Galadriel left by the end if the second era after the last alliance of men and elves and the war with Sauron.
[1] which I think is also half Teleri.