I'm another who doesn't like
Mackenzie and my concern would be that she would feel like had the name that "didn't fit" because
Leo and
Maeve are both short and old-fashioned and Mackenize is long and trendy.
I love your three other choices!
Anya's my very favorite, but they're all great.
Leo and
Anya in a sibset feels very Tolstoy, but in a good way and I think
Maeve still fits well.