haha, I find it ironic that you say you prefer the [name]Emmeline[/name] spelling for the double "M"s, but you keep spelling it [name]Emaline[/name].
I personally am all for [name]Emmeline[/name]–I believe either [name]Emmeline[/name] or [name]Emeline[/name] is the original French spelling–but I just thought that was interesting. 
I adore [name]Emmeline[/name], personally–it used to be my favorite girls’ name, fell off for a while, and now it’s back and I still really love it! I think something like [name]Emmeline[/name] [name]Starla[/name] is fine, although [name]Starla[/name]'s not really my thing–it doesn’t sound any longer than something like [name]Elena[/name] [name]Charlotte[/name] or [name]Aria[/name] [name]Lucy[/name], and neither one of those seem disproportionately long (at least, imo!). Then again, I’ve had 3 [name]Emmeline[/name] combos I’ve loved enough to add to my list ([name]Emmeline[/name] [name]Olivia[/name], [name]Emmeline[/name] [name]Ruby[/name], and [name]Emmeline[/name] [name]Poppy[/name] (my current combo! Och, love)), and they’re all more than one syllable. And I plan on using a second MN to honor family.
I also considered these, if they interest you:
[name]Emmeline[/name] [name]Charlotte[/name]
[name]Emmeline[/name] [name]Kaia[/name] (still adore the contrast between these two!)
[name]Emmeline[/name] [name]Cosima[/name]
[name]Emmeline[/name] [name]Lucia[/name]
[name]Emmeline[/name] [name]Lydia[/name]
[name]Emmeline[/name] [name]Leona[/name]
[name]Emmeline[/name] [name]Fiora[/name]
[name]Emmeline[/name] [name]Felicity[/name]
[name]Emmeline[/name] [name]Fiona[/name]
[name]Emmeline[/name] [name]Clara[/name]
[name]Emmeline[/name] [name]Cora[/name]
[name]Emmeline[/name] [name]Noelle[/name]
[name]Emmeline[/name] [name]Lyra[/name]
[name]Emmeline[/name] [name]Lila[/name]
[name]Emmeline[/name] [name]Lily[/name] is very pretty, too!
If you want a one-syllable MN, what about:
[name]Emmeline[/name] [name]Liv[/name]
[name]Emmeline[/name] [name]Jane[/name]
[name]Emmeline[/name] [name]Kate[/name] (considered this myself, and still might use it as a second middle–I quite like [name]Emmeline[/name] [name]Poppy[/name] [name]Kate[/name]!)
[name]Emmeline[/name] [name]Hope[/name]
[name]Emmeline[/name] [name]Joy[/name] (very sweet!)
[name]Emmeline[/name] [name]Grace[/name] (meh, [name]Grace[/name] is often seen as a filler MN, but since it’s my grandmother’s MN, I rarely see it as so. With no significance, though, it might seem kind of trite and blah, though)
[name]Emmeline[/name] [name]Fleur[/name] (so French! I love it!)
[name]Emmeline[/name] [name]Tess[/name]
[name]Emmeline[/name] [name]Pearl[/name]
[name]Emmeline[/name] [name]Eve[/name]
[name]Emmeline[/name] [name]June[/name]
[name]Emmeline[/name] [name]Bay[/name]
[name]Emmeline[/name] [name]Greer[/name]/[name]Emmeline[/name] [name]Grier[/name] ([name]Grier[/name] is one unisex name I absolutely adore–I think [name]Emmeline[/name] [name]Grier[/name] is fab!)
[name]Emmeline[/name] [name]Ruth[/name]/[name]Emmeline[/name] [name]Rue[/name]
I think [name]Emmeline[/name] [name]Johanna[/name] would be a beautiful combo, too, although it doesn’t really seem to fit anything you’re looking for. 
Good luck!