If two characters are on the same age here it just means there the same age not that there siblings or anything (side characters like say Amber and Lantern well not be included)

Arora: 5
Mint and Firefly: 6
Sunset and Shadowseer: 7
Snowstorm Terra and Mesa: 8
Leatherback: 12
Hurricane: 13
Crow: 14
Skylight and Phoenix: 16