"But now Thingol lay dead, and his spirit had passed to the halls of Mandos; and with his death a change came also upon Melian. Thus it came to pass that her power was withdrawn in that time from the forests of Neldoreth and Region, and Esgalduin the enchanted river spoke with a different voice, and Doriath lay open to its enemies.
Thereafter Melian spoke to none save to Mablung only, bidding him take heed to the Silmaril, and to send word speedily to Beren and Lúthien in Ossiriand; and she vanished out of Middle-earth, and passed to the land of the Valar beyond the western sea, to muse upon her sorrows in the gardens of Lórien, whence she came, and this tale speaks of her no more."( "The Silmarillion")
(Here Melian is looking not quite like herself - because of that "change" in her, or because I didn't manage to draw her face properly...)