I have lived with the name Amberly my entire life, and I must say that I've grown to adore it. Those of you saying it's "too made up" or "not even pretty" probably have boring names. Opening your mind to the possibility of beauty in unordinary things is such a wonderful experience if you simply allow it to happen. Also, everywhere I've looked, I've always read that the name means 'a gem." Quite interesting, especially for a person living in the Gem State.
I'm surprised to say that Amberly is better than Amber. In fact, I much prefer other forms of it such as Ambra or Anbar. Amber seems weak and boring compared with them. Amberly instead shines more and has the same lovely vibe of Cindy or Shirley. I'd use Lëa or Berry as nicknames.
Don't think I've ever seen amber turned into an adverb before! How exactly would someone do something "Amberly"? Would they move so slowly as to appear solidified in sap?Amber is actually a name I like, but I don't think parents who choose Amberly for their daughter - especially if they are English speakers - are thinking this one through.
I like the name Amberly partly because you could use Amber as a nickname for it, also because it sounds beautiful as a whole. In the Selection series by Kiera Cass the Queen's name is Queen Amberly.