Who cares if they're similar? My mom's brother's name is Christopher, she married a Christopher, and had a son, named him Christopher. What's the big deal with using the same names these days? And plus, I would say that Averly and Everleigh are different enough that you shouldn't worry about it.
I think having the same name is actually easier than something that is so similar that the extended family is constantly slipping and confusing the names.
I speak from experience; I have five male relatives with the same name, and we all know which is which, no confusion among family (unless you deal with credit rating mix ups, but that is another subject all together).
But I named my son a name that on paper looks totally different from my nephew's name, but when spoken, they sound kind of similar. Even I get their names mixed up when we are together and my parents (the grandparents) are always calling them the wrong name. It's not the end of the world, but it is something I never thought about when considering the name.