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[cellurdur]

Originally Posted by William Cloud Hicklin

We can never know now; but it is the case that not only was G "an Elf-lord from a house of Princes", he was also, in the old version, the chief or lord of the House of the Golden Flower. This inplies very high rank even among the Noldor of Turgon's following, and so kinship either to the house of Finwe or of Inwe (or both) on the distaff side is not impossible.

(In another forum we worked out not long ago that if Gil-galad is restored to his proper place as Orodreth's son, then the Noldor practiced pure Salic succession and kingship descended neither to nor through females)

As you say we will never know for sure unless Christopher Tolkien decides to use his right to decide cannon.
When speaking about his ban it says this.

'he did so reluctantly because of kinship to Turgon and allegiance to him.'

The kinship to Turgon being stressed over Fingolfin along with the golden hair is what leads me to believe that at least on his mother's side Glorfindel was a relative of Elenwe.

As for the Noldor succession it seems quite a straight forward salic law as you said. After Gil-galad's death there was nobody left in ME with a claim to the High Kingship.