I like it better as a first name, but I'm a bit biased because I have it as a middle and am not a fan.
Elizabeth and
Katherine are a pretty classic and common sibset (at least where I grew up) so you can't go wrong. I know of 4 sibsets from growing up that had
Elizabeth and
Katherine as siblings; two went by
Beth and two went by
Liz.
Ellie would help it feel a bit more modern with the other
El- names around.
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