The name Lórellin doubtless refers to the fact that this was the place where Estë slept, but the Elvish root relates to dreams and dreaming as well as simply sleep. The name therefore also has a connection to Estë's spouse, Lórien the master of dreams, in whose gardens it lay.

The text here is a little ambiguous. In the Valaquenta, after describing the lake itself, we're immediately told 'From the fountains of Irmo and Estë all those who dwell in Valinor draw refreshment...' Its not entirely clear what these 'fountains' are: presumably this is a reference to the springs that fed Lórellin.