Sindarin name for: "She who came from the waves". Or something close.

Hi there, I'm here to know if there's a way to create a name for a character that i need for a RPG Champaign in the Middle Earth setting. This name is supposed to be the one for a female Maia that appears as an Istar in the shape of an old woman. In my lore is supposed to be a Maia of Ulmo, thus her name should be related to the sea. However i need both a sindar name and a quenya one. How can i call her?

I would offer:

Falfien (S. wave-daughter)

I'd recommend Falvien to reflect the pronunciation/etymology of falf [falv].