The name of the Goddess Hathor written in hieroglyphics:
" Ḥ(w)t-Ḥr(w) " ,
whose egyptian pronunciation preserved in Coptic (that is the last stage of the Egyptian language) is
" Hathór "
The stress falls on the "ó", that is a pure high vowel and is pronounced like the "ó" of the english words "note", "omen".
Concerning the pronunciation "Het-Hert/Het-Heret/Het-Heru", it is simply a conventional reading invented by the scholars and it does not reflect the real pronunciation of the Egyptian language (as it is written at the beginning of every grammar of hieroglyphs).
Detail from the "Temple of Millions of Years" of Queen Hatshepsut, west 'Uaset'-Thebes.