DISCLAIMER: The Cities and Planets are usually not inhabited in my Lore.
The cities are summoned by the characters as a means of stress reduction, not to destroy entire civilisations.
But I leave it up to your imagination to decide whether the cities are inhabited or not.

Maya
Takao-Class Heavy Cruiser, 3rd in her Class. She has a lively personality, and the most hot-tempered among her sister. She has insanely strong powers, which are so overpowering that she can unconsciously change or summon things with them. Sometimes, she even teleports other Shipgirls into paralell worlds, in which they are confronted with the local circumstances. Some of her comrades might have got the size fetish as a result.
In her spare time, she creates parallel universes in which she transforms herself into a Mega or Tera Giantess and dominates cities and entire planets with her size. She loves the feeling when entire civilizations look up to and worship her so that she doesn't destroy them.
Mostly, however, she creates uninhabited planets and cities which she demolishes at her pleasure.
Her favorite pleasure is the crunchy feeling of a city being crushed under her foot.

Choukai
Takao-Class, Heavy Cruiser, 4th in her Class. She has a calm and collected personality, usually described as the most soft-spoken of all the Takao-Class sisters. Like Maya, she possesses insanely strong powers, which she can control much better.
Mostly she limits herself to shrinking cities and planets, and summoning them in her room. Sometimes she also needs the pleasuring kick and creates parallel universes in which she enjoys the dominating size of a Tera-giantess.
What she enjoys the most is showing off her gigantic size in front of a shrunken city and crushing them under her weight..