Silmarien - is a Tolkien-ian reference to a descendent of Elros. She was five generations down from Elros, so, she has Elven Blood - because Elros's father was Earendil Half-Elven, and his mother was Elwing who was also Half-Elven.
You Tolkien-heads here, may recognise Silmarien's name. She was fifth in line to the succession of the Throne in Numenor, but the Law at the time prohibited her ascention to royalty. So, the Throne went to her first cousin instead.
The Line of Elros eventually failed through her first-cousin - albeit several thousand years downstream. However, Silmarien's descendents protected the Line of Elros - and this line became known as "The Faithful" because they did not succumb to the Vanity and Arrogance that lead to the ruin of the Ruling Line of Elros. Elendil the Tall, and his sons Isildur and Anarion were descended from Silmarien as was Aragorn.
It was also Silmarien's line who retained ties with the Elves of Alqualonde - where most others in Numenor turned away from the Elves in jealousy, pride and resentment. And, it was through The Faithful's ties to Alqualonde that the Palantiri were bestowed upon Silmarien's Line by Elves who once visited the shores of Numenor.
Before the Akallbeth (the Downfall of Numenor), a seed was rescued from the White Tree in Numenor. This seed was a direct descendent of the Tree of Silver - Telperion - and was brought to Middle Earth by The Faithful after the Drowning of Numenor.
When the Numenoreans amassed the greatest Army ever seen in Arda - and sailed to wage war on Valinor in the Uttermost West, the Valar laid down their Guardianship of Arda and Eru - The One - intervened and opened the earth, swallowing the Numenorean fleet.
However, Silmarien's line sailed to Middle Earth in Nine Ships. Tolkien's poem speaks to the epic migration of The Faithful to Middle Earth.
Tall Ships and Tall Kinds
Three Times Three
Seven Stones and Seven Stars
And One White Tree
Silmarien's Heir - Aragorn - married Arwen, and the long-sundered lines of Elros and Elrond were brought back together again by this Union.
