Are Zadie and Zella too close for fictional sisters?

In the book I’m working on just now, my main character [name_f]Zadie[/name_f] has a twin sister who died as a toddler. I really like the idea of a name with Z for her.

[name_f]Do[/name_f] you think [name_f]Zella[/name_f] would be too close? She is a [name_m]Minor[/name_m] character in the book as a ghost. I’m also considering [name_f]Hazel[/name_f] for her.

[name_f]Zadie[/name_f] and [name_f]Hazel[/name_f] sound much better together. [name_f]Zadie[/name_f] and [name_f]Zella[/name_f] is a little too…contrived.

I prefer [name_f]Zadie[/name_f] and [name_f]Hazel[/name_f], personally. [name_f]Zadie[/name_f] and [name_f]Zella[/name_f] could work but it definitely sounds like the name similarity was on purpose.

[name_f]Zadie[/name_f] and [name_f]Hazel[/name_f] make a great sibset!

[name_f]Zadie[/name_f] and [name_f]Zella[/name_f] would work better if they were constantly talked about as a pair, or were identical twins. For a main character and her late sister, I think [name_f]Zadie[/name_f] and [name_f]Hazel[/name_f] works much better!