Hey, this is actually, to my knowledge, quite a new way of asking riddles, and shouldn't be left to die!
And the first answer could be
Nimrodel again:
1. Stream = her namesake
2. Song = the one Legolas sang
3. A Balrog = Durin's Bane, whose awakening by the Dwarves was the reason for her and Amroth's emigration plans
(4. got lost - like Nimrodel herself
)
5. Havens - of Edhellond, where they planned to set sail
6. Aman - final destiny which she never reached