I’m having a hard time settling on a name that feels right with both [name]Fable[/name] [name]Grace[/name] and [name]Iris[/name] [name]Claire[/name]. Any suggestions berries? 
Before seeing what [name]Fable[/name]‘s middle name was I was assuming boy, so I’d def go with something thats not a gender neutral name. Are there any boys’ names you are considering?
[name]Fable[/name], [name]Iris[/name] and
[name]Everett[/name]
[name]Malcolm[/name]
[name]Grady[/name]
[name]Lachlan[/name]
[name]Callum[/name]
[name]Julian[/name]
[name]Jasper[/name]
Kipling
[name]Steen[/name]
[name]Vaughn[/name]
[name]Miles[/name]
[name]Sterling[/name]
[name]Thaddeus[/name]
[name]Rowan[/name]
[name]Reid[/name]
[name]Quincy[/name]
[name]Ned[/name]
[name]Hope[/name] this helps
[name]Theodore[/name]
[name]Jasper[/name]
[name]Gregory[/name]
[name]Gage[/name]
[name]Roman[/name]
[name]Rainier[/name]
[name]Quincy[/name]
[name]Ulysses[/name]
[name]Ezekiel[/name]
[name]Ezra[/name]
Hmm… what kind of names have you been looking at thus far that have been closer to what your hoping to find?
[name]Fable[/name] and [name]Iris[/name] both have very different feels to them ([name]Fable[/name] feel very modern, [name]Iris[/name] feeling quite antique), but they both are ‘word names’ as well ([name]Fable[/name] = a story; [name]Iris[/name] = a flower). So perhaps another ‘word name’ may match the sibset best:
[name]River[/name] is the first one that comes to mind that seems to fit well.
Here’s some others possibilities that I grabbed from a different thread (Nameberry - Welcome to the Nameberry Forums) about word names:
[name]Calix[/name]
[name]Axel[/name]
[name]Quill[/name]
[name]Penn[/name]
I’m not particularly well-versed in good ‘word name’ names, so I’m sure there’s some better possibilities then some of these out there. But I do think [name]River[/name] would be a pretty awesome name in combination with your sibset, combined with a common/classic middle name.