I'm not sure why you're asking about Norwich City, unless you think Amelia might have mistaken her for a moving ship and tried to signal her.
Not only was the Norwich City stationary, she arrived at that location by being off course. I often imagine with a shudder what it was like to hit that reef in the dark and stormy night when they didn't even know it was there. And if they'd been just a smidgen to the left of that course, they'd have missed it entirely and probably never known what a close call they'd had.
As far as Amelia was concerned, there's no indication she had ever heard of the Norwich City before the flight. There are, of course, credible radio messages in which she may be attempting to have listeners identify her location by giving the name of the shipwreck. This also supports the likelihood that neither she nor Fred knew much, if anything, about Gardner Island in advance of landing on it.
LTM,
Don