The June 2008 issue of NEHGR (162:113-4) says that in 1990 someone found a marriage license dated 18 Sep 1609 for William Gillett clerk and curate of Kingstone, Somereset, and Habiathia Pye of Donyatt, Somerset.
I have seen her death date given as 14 May 1681 at Chaffcombe, but the only source was the LDS Ancestral File. Whether Habiathia was the mother of all of William's children is uncertain as some birthdates may have been before the date of the license.
The article also provides proof that Jonathan Gillett was William's son. The will of Rev. William Tyes mentioned "Jonathan Gillet the sonne of Will[ia]m Gillett Clarke p[ar]son of Chafecombe in the Countie of Soms[e]t ..."
Most likely nothing more is known of Habiathia since there has been extensive research on the Gillett family.