Ilmarë is a Maia whose story was never really told. However, some importance must have been attached to her:
“Chief among the Maiar of Valinor whose names are remembered in the histories of the Elder Days are Ilmarë, the handmaid of Varda …”
In early versions of her story, Ilmarë (previously known as Erinti or Ilmar) was the daughter of Manwë and Varda, and along with her brother Fionwe Úrion (~Eönwë), they were the eldest of the children of the Valar. However, Tolkien soon disregarded that notion, along with the associated concept that the Valar could have offspring, and Ilmare’s role was changed to being the Handmaid of Varda.
Little else is known about her. Something about her role may be deduced from her name. Ilma is the Quenyan word for starlight, and it would seem likely that there is also an association with the word Ilmen, the area above the Earth where the Stars flame in space.