Egyptian goddess, wife and sister of Osiris (4)
I believe the answer is:
isis
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">egyptian goddess</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >'<span class="explanation-format__original">wife and sister of osiris</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for isis that I've seen before include "The upper Thames" , "Sister of Osiris" , "Si, si - an Egyptian goddess" , "To be, to be an Egyptian goodess" , "Divine female" .)