The climax (and possibly sole reason for this Sydney excursion) was dining at the Quay Restaurant. Yes, the sister had booked us in months in advance and she made sure we arrived well ahead of time, in our best appearance, of course. Thankfully for us, the weather had been kind and we managed to venture the surrounding area prior to our booked dinner time.
The restaurant staff were very professional and attentive towards our needs, which is always a positive gesture, especially when good ambience = happy visitors. We studied the menu a week before we landed in Sydney and hence, were just stuck on the task of deciding what to drink!