That is correct. The meaning of the sentence with and without the ghaH would be exactly the same, so the presence of it in this sentence might be emphasizing just a little that it was HER (or HIM) and not you or me or somebody we haven't yet spoken about. In English we do it all the time with our voice, but we don't have a good way to do it in writing. I guess sometimes bold or all caps works, but it's nice to have an easier way to do it in written Klingon.
Indeed, although in this case it also serves to resolve some potential ambiguity: Without the ghaH, other possible subject would be 'oH ("it"), chaH ("they (who are capable of language", i.e. a group of people) or bIH ("they (that are not capable of language)", i.e. a group of animals).