I’m not sure why they couldn’t be a sibset. They aren’t very similar, except for being literary and classic.
I really like
Beatrice, which makes me think of
Dante, as well as Shakespeare. However it is pronounced different ways and it feels like a bit of mouthful of vowels to pronounce, for me personally and it feels more formal. I like
Bea for short, but then I don’t get to use the grander name.
Alice is classic, short and sweet. And I get to say the whole name as much as I want.
Alice and
Bea would be cute on sisters.