[name_m]Don[/name_m]'t worry! There are so many beautiful names out there and it might take until seeing her in person that something perfect dawns on you. For what it’s worth, I don’t think [name_f]Annabelle[/name_f] [name_u]Ellis[/name_u] sounds bad, but you could always use [name_f]Annabella[/name_f]. I think [name_f]Annabel[/name_f] [name_u]Ellis[/name_u] might make the repetition less noticeable. A few other options:
[name_f]Alana[/name_f] - Similar sound to “[name_f]Olivia[/name_f].” [name_f]Alana[/name_f] [name_u]Ellis[/name_u] has a nice flow, in my opinion.
[name_f]Amelia[/name_f] - You seem to like modern classics ([name_f]Ava[/name_f], [name_f]Chloe[/name_f], [name_f]Olivia[/name_f]) with nickname options, and [name_f]Amelia[/name_f] checks all those boxes. You could nickname her “[name_f]Mia[/name_f]” or “[name_f]Millie[/name_f].” You could also go with [name_f]Emilia[/name_f]. Or you could use [name_f]Amalia[/name_f] with the nickname “[name_f]Mollie[/name_f].” (I’ve really loved this name ever since I heard [name_f]Amalia[/name_f] by [name_f]Melody[/name_f] Gardot…it’s such a beautiful song for a daughter).
[name_f]Annabeth[/name_f] - if the -elle ending to [name_f]Annabelle[/name_f] is the problem, maybe you could consider [name_f]Annabeth[/name_f] instead?
[name_f]Aviana[/name_f] - this feels similar to [name_f]Olivia[/name_f] to me because of the ‘v’ and the four syllables, but it isn’t so close that it’ll seem strange with a cousin. You could use the nickname “[name_u]Avi[/name_u].”
[name_f]Charlotte[/name_f] - like [name_f]Annabelle[/name_f], [name_f]Charlotte[/name_f] has a sweet, Southern belle sound, and an elegant silent ‘e’ ending. Possible nicknames include [name_u]Charlie[/name_u], [name_f]Lottie[/name_f], [name_f]Char[/name_f], etc…
[name_f]Cecilia[/name_f] - has sort of a similar look to [name_f]Olivia[/name_f] with the same -ia ending, and “[name_f]Cece[/name_f]” is an adorable nickname.
[name_f]Daphne[/name_f] - similar bright, vibrant appeal that [name_f]Chloe[/name_f] and [name_f]Ava[/name_f] have, but has a bit more substance.
[name_f]Delilah[/name_f] - sort of a drawn out version of [name_f]Isla[/name_f], for which you could use [name_f]Isla[/name_f] (or [name_f]Lila[/name_f]) as a nickname.
[name_f]Juliette[/name_f] - [name_f]Juliette[/name_f] feels sweet and romantic the same way [name_f]Annabelle[/name_f] does, with plenty of nickname options ([name_u]Jules[/name_u], [name_u]Julie[/name_u], etc.) You could also spell it [name_f]Juliet[/name_f] so that the E doesn’t run on with your last name.
[name_f]Lucy[/name_f] - I’m mostly recommending this because [name_f]Lucy[/name_f] [name_u]Ellis[/name_u] just sounds so sweet to me. But it also does have some of the elements of the other names you like, like the -e ending from [name_f]Chloe[/name_f]. You could also use [name_f]Lucia[/name_f] to get the -ia ending from [name_f]Olivia[/name_f] and nickname her “[name_u]Luce[/name_u]” or “[name_f]Lucy[/name_f].” For both, you could use the nickname “[name_f]Lu[/name_f].”
[name_f]Madeline[/name_f] - [name_f]Madeline[/name_f] just sounds sweet and lively, the same way [name_f]Annabelle[/name_f] does. [name_f]Madeleine[/name_f] is another option.
[name_u]Ruby[/name_u] - like [name_f]Annabelle[/name_f], this name is feminine and beautiful but has a lot of personality.
[name_f]Savannah[/name_f] - again going off of the “Southern belle” appeal, and it has “[name_f]Ava[/name_f]” in it. [name_f]Savannah[/name_f] [name_u]Ellis[/name_u] sounds/looks so perfect to me. [name_f]Savannah[/name_f] has quite a few nickname options as well. It also has that “anna” sound in it.
[name_f]Scarlett[/name_f] - similar appeal to [name_f]Charlotte[/name_f], but a bit more romantic; tradeoff is you have fewer nickname options.
[name_f]Violet[/name_f] - [name_f]Violet[/name_f] is a personal favorite of mine and I think it has similar appeal to some of the names on your list. [name_f]Violet[/name_f] and [name_f]Isla[/name_f] have similar sounds, it has the “v” from [name_f]Ava[/name_f] and [name_f]Olivia[/name_f], and a pretty, feminine ending.
[name_f]Vivienne[/name_f] - [name_f]Annabelle[/name_f] and [name_f]Vivienne[/name_f] are both romantic and feminine, with sweet nicknames ("[name_f]Annie[/name_f]" or “[name_f]Vivi[/name_f]”). Actually, if you were hoping for the nickname “[name_f]Annie[/name_f],” you could get it through this name by spelling it [name_f]Vivianne[/name_f].
Good luck!