Olwë

Olwë appears to have belonged to the first generation of Elves, who awoke at Cuiviénen rather than being born. If this is true, however, it's hard to explain the fact that he had two brothers, Elwë; and Elmo, so it is at least conceivable that he was born while the Elves still lived in the distant east, rather than awakening there.

The -wë element of Olwë's name means 'one' (as for example in Ingwë 'first one' or Finwë 'skilled one'). The ol- syllable, however, is obscure. It is possibly related to the same root ulu- seen in the name Ulmo, meaning 'pour' or 'flow', but there is no direct evidence to support this idea.

Eärwen is the only child of Olwë mentioned in The Silmarillion, and so she is the only one shown here. However, in a comment reproduced in volume 10 of The History of Middle-earth, it's stated that 'Ingwë and Olwë beget many children'. This idea doesn't reappear elsewhere, and may well have been abandoned, but it does at least leave open the possibility that Olwë had many other unnamed children apart from Eärwen.