Yes, she's your "Elder" sister.

I mean if centaur can get away with calling Mutsukis elders then this works perfectly fine

If you ask Amagi herself, she'll only respond with either a soft chuckle OR imply that she's the product between her and the Commander's love as per the shady ass cubes

The funny thing is Akagi is older, if you go by the laid down date.

This is the hilarity of ship classes.

“We fucked up the construction to get her back and stuff so we had to do a factory reset”

O_O