All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
There is no harm, Inshaa' Allaah, for a woman to remove the hair that is underneath the eyebrow provided that this hair is separate from the hair of the eyebrow, as this takes the ruling on which the Islamic legislation has kept silent, i.e. did not state whether or not it can be removed. So it is permissible to remove it especially if by its existence it disfigures the creation (the natural look).
Allaah Knows best.