AspectOrdinary pronounPronoun of affair/story
ReferentA previously mentioned or known entityThe proposition supplied afterward
FunctionAvoids repeating the nounPrepares the listener for an important report
InterpretationFrom the preceding contextFrom a following clause
In «هند جميلة وهي مجتهدة», «هي» normally refers to Hind. By contrast, if «هي هند مليحة» is analyzed as an affair/story construction, the clause that follows explains the pronoun. This is the foundational analytic difference.