I think [name_f]Amelia[/name_f] and [name_f]Daphne[/name_f] are great together! I think both carry a vintage, feminine feel, yet neither one is too commonplace or bland. [name_f]Amelia[/name_f] feels a tad more cozy, whereas [name_f]Daphne[/name_f] is a little more buttoned-up, but together they play off one another nicely.
Of the other names you mention, I absolutely don’t think [name_f]Eliana[/name_f], [name_f]Gabrielle[/name_f], or [name_f]Arielle[/name_f] fit with [name_f]Amelia[/name_f]. They feel more modern - though they really aren’t, I realize - and also much more glam. [name_f]Miriam[/name_f], perhaps, is a little too staid, whereas [name_f]Amelia[/name_f] feels more lively and vibrant. I could potentially see [name_f]Eloise[/name_f] with [name_f]Amelia[/name_f], though she has a bit more sweetness to her. I do like that pairing most off your list there.
I don’t find [name_f]Daphne[/name_f] harsh. Sure, she isn’t lilting. But, she is rather ethereal, elegant, and suave. [name_f]Amelia[/name_f] doesn’t have a strong sound in her. Each one, from the gentle “ah” beginning to the anchoring “ME”, to the feminine “[name_f]Lia[/name_f]” at the close, creates a soft, melodious rhythm. [name_f]Daphne[/name_f], however, partly due to her comparable shortness and partly due to that strong initial “dah” sound, feels [harsh] in comparison, but I prefer sturdy. When paired with the light “ph” sound, though, and the effortless ending “ee,” she doesn’t feel too cold next to [name_f]Amelia[/name_f]. She merely seems anchored to me. Again, I’ll use the phrase “buttoned-up,” which I would also use for something like [name_f]Charlotte[/name_f].
I’d love to see [name_f]Amelia[/name_f] and [name_f]Daphne[/name_f] together. They create a striking, strong, ladylike sibling set, with a perky, gentle, vintage image. [name_f]Daphne[/name_f] is an interesting name because she’s really never been “popular” in the way we think of it, in terms of numbers. Not even in the 1880s. [name_f]Daphne[/name_f] started her ascent in the late 1920s, saw some growth in the 40s, but really saw the most use - still not what we’d deem popular use - in the 1960s. She’s just in the last year started to climb back toward her heyday usage level, and she’s sure to climb further up the charts. Still, she’s not going to be one of those uber-popular vintage names, as her style doesn’t lend toward the style we latch on to today - the short, the sweet, and the frilly feminine ([name_f]Ella[/name_f], [name_f]Elsa[/name_f], [name_f]Lily[/name_f], etc.) or the simple, stylish, and strong ([name_f]Charlotte[/name_f], [name_f]Hazel[/name_f], [name_f]Alice[/name_f], etc.); [name_f]Daphne[/name_f] is more in the second camp, but she’s got more of a grown-up feel that must be off-putting to some, although I think she fits a little one beautifully as well, and I personally adore her! [name_m]Just[/name_m] for kicks, I’ll tell you that [name_f]Amelia[/name_f] is a name that has been perennially popular from the 1880s, commonly used for ladies, falling just slightly out of favor - but really not out of favor, more to the current level of [name_f]Daphne[/name_f]'s usage - from the 40s to 70s and then really surging to popular usage in the 2000s, reaching an all-time high of #17 just last year! [name_f]Amelia[/name_f] has a lot going for her, from that smart A start, to the girly sweet [name_f]Lia[/name_f], to the plenty of nicknames, to the lilting, elegant sound, to the [name_f]Amelia[/name_f] [name_f]Earhart[/name_f] strong association. [name_m]Even[/name_m] so, [name_f]Daphne[/name_f] is a powerful punch to bump up an [name_f]Amelia[/name_f] sibling set, adding a unique edge to a thoroughly vintage set and an flair of elegance to two ladylike names.