I'm polishing and redrafting my novel. But grammar is not my strong suit. I need help with tenses, specifically. As you may already know, stories are usually told in the past tense. But it's not always simple past. There's past perfect, as well. Could you please help me with this particular sentence:
Megan couldn't remember how long she has been sitting in her armchair, staring at the empty wine glass in her hand.
Should it be "she has been sitting" or "she had been sitting"?