What does Naava mean?
From Hebrew נָאוָה (na'avah) 'beautiful, comely, pleasant', as in the Song of Songs ('I am dark and beautiful'). The sense covers both 'beautiful' and 'pleasant/fitting'.
What does Yaffa mean?
From Hebrew יָפֶה/יָפָה (yafeh/yafah) 'beautiful, lovely'. Yaffa (also Yafit) is a modern Hebrew beauty name; the same root names the city Jaffa ('the beautiful').