A nice and interesting sci-fi story,
It feels like a comic book.

Hopefully not too negitive.
There were a few times that could have used better editing.("Who's talking? Oh it says 3 paragraphs up.")

First off I gave to admit the authors note in the beginning really threw me off from the context of the story. Since it was not explicitly implied in the first chapter, I assumed the setting was modern day America with the alien civilization being of a more advanced state compared to there's, but as I read the second chapter I didn't notice any real anachronisms affecting the story, like no out of place technology like cellphones or internet which wouldn't exist in a society in the 1930's. I am curious as to why the need to make it AU instead of just having it take place in an earlier time. What else is different in this reality that stands out from our own? Rocket technology didn't exist from 30's era tech, let alone the splitting of the atom, so maybe Lottie will use her knowledge from the technologically superior homeworld to play a part in there development later in the story?

The opening sentence is redundant as you mention it being a bright sunny day twice. The sentence also seems rather tame for an opening along with the other mundane act of killing weeds. I don't think much would be lost to the story if this part was taken out and the story started with the news report on the robbery.

As a character I like Leo the most out of all of them. While your usual flare for green skinned heroines is back in this piece there's something interesting about an alien vigilante fighting crime. I liked the backstory she gave on her homeworld as it differs vastly from earth. On a scientific note I liked how you explain away the crystals being used to store excess heat for their cities as the planet would be too cold to support life as we know it.

Lottie comes across a a sympathetic character, having her homeworld destroyed and you play on her innocence and vulnerabilities well.

This was an interesting idea. Going with the green-skinned woman again, she seems to be in all of your stories. I liked the world-building in this chapter and how the sci-fi element is explored. Particularly with this new planet, I like all the stats. Like how the sun gets the other world only a quarter as much sunlight and how the oceans became marshes and how the crystal cities needed energy from the planet's core. I do wonder if the pieces of the destroyed world really will be able to maintain the planet's gravity. Not if it imploded right? If it was some radiation anti-matter technology I don't think it would work but it's not a major part of the story so I'm sure there's some explanation. Leo is an interesting character and so is Lottie. I'm not sure what role Leo will have later on in the story but I think this might be a sequel so it makes sense. If I could critique anything I'd say it would be the feel of the realness, it doesn't feel gritty enough for my tastes. Maybe it's just Leo's superhero status. This is just a feel thing so personal though.