Is it too much to have a sibset consisting of four girls whose names all have the the same amount of syllables and end with – ia? Each name is very different aside from the “ia” part.
No, I don’t think it’s too similar at all! I’m going off of the “-ia” girl names in your signature, and they’re all very much distinct from one another. It’s a subtle pattern; I doubt too many people will notice it, but it serves to increase the cohesion within the sibset. I like it!
Agree with PP. It’s more of a subtle pattern. If your girls have different enough-sounding syllables it shouldn’t make a difference. For example, in your signature, [name_f]Aurelia[/name_f], Meridia, & Evaria sound lovely together 
Definitely not too much at all.
I don’t think it is too much. That being said, I wouldn’t do it because to me it seems too matchy. [name_m]Reading[/name_m] the pp’s example set makes me wish there was more variety. That is my personal style coming through, though.
I personally feel like it is too much, not the fact that they all have the same amount of syllables (which isn’t noticeable) but that they all end with -ia ([name_f]Aurelia[/name_f], [name_f]Lydia[/name_f], Meridia, Evaria). It’s confusing to me and I have a hard time remembering their names. I also think the names loses abit of its’ originality when all the siblings sound the same at the end of their names. That’s what I think.
No, I don’t think that it’s too much.