What would you name ___'s sibling?

Girl: [name_f]Kate[/name_f]
Boy: [name_m]Jack[/name_m]

[name_m]Harvey[/name_m]?

Girl: [name_f]Arleigh[/name_f]
Boy: [name_u]Carson[/name_u]

[name_f]Tillie[/name_f]?

Girl: [name_m]Kelbie[/name_m]
Boy: [name_m]Eric[/name_m]

[name_u]Logan[/name_u] (g)?

What would you name [name_u]Logan[/name_u]'s (g) sibling?

[name_u]Blake[/name_u] (G)

What would you name [name_u]Kit[/name_u]'s (g) sibling?

We’re supposed to use both genders here.

Girl: [name_f]Lily[/name_f]
Boy: [name_m]Maceo[/name_m]

[name_f]Megan[/name_f]?