Elissa Dumas is a level 35 portal trainer located on the first floor of the The Temple of the Moon in the night elf city of Darnassus. She seems to be busy in some kind of conversation with Rukua and Droha. Her cousin Torgal died during Arthas's attack on Icecrown.
You need to be at least level 30 to learn the Teleport Spell to Darnassus, and at least level 50 to learn the Portal Spell to Darnassus.
She may be related to Maginor Dumas.