No they are not. The width of the panels look too skimpy I'm afraid. I recommend sheers on bay in a more generous fullness.

Did the professional fabricate the curtains as well? Or just hang them? I think they are definitely too high, and they don't have any heading which makes them look a bit unfinished. They don't look interlined either, which gives them a stiff look--they aren't properly "dressed." Where and how are you hanging the sheers? They usually are set underneath the main curtains, so you'd need a double rod. As for how many you need, that depends on the window dimension, which isn't given.

I'd consider calling in a curtain designer to help you--that window is fabulous and would really look great if it were done well.

I would recommend lowering the rod somewhere between the top of the window and the ceiling. This would allow the rod to stand out. If you "puddle" the draperies it will give the appearance of greater fullness.

I'm curious...I thought it was a decorating trend to put the rods very close to the ceiling...but it does look awkward in this photo. Looks like the curtains are meant to be decorative framing and not functional. I have 12' sliders I'm contemplating drapes for so I will be interested to learn more.

Close to the ceiling but not abutting it is best in most cases. I would bring them down 3-5 inches. I would also add 2 more panels to the large center window. You will need a double rod to do sheers correctly (it will look too bunchy all on one rod and won't be functional). The number is goi g to depend on your measurements, but you want them to gather at least a bit so you would want 1.5-2 sheers per full sheer width minimum. (if your sheer panels are 50 inches wide, they should cover only 25-35 inches of window at most for example) My best eyeball guess would be 1-2 for each side panel and 4-6 for the larger window.