I find that the cover fits your story extremely well, especially since it is about a superhero. I could imagine the story as a comic, and your cover fits that image quite nicely. The title is also a nice fit for your story, and it provides enough information that your audience has a general idea of what the story may be about without spoiling any parts of it.
Chapter 1: "Rays of blue, purple, and pink light were emanating from Wendy's hands, right into I19 beady eyes." Here, you should write "I19's" to show that the beady eyes belong to I19.
Chapter 1 & Chapter 2: Every now and then, I noticed some missing or misplaced commas. Although your grammar and writing is great overall, be sure to keep an eye out for some sections missing punctuation.
I think the plot of your story is very interesting and quite original. I loved how you incorporated Wendy's background and past experiences into the first chapter, and you made it clear how she ended up where she is now. I found that the writing style also fits the story quite well, and you seem very comfortable and focused on your story. For some genres, deep, descriptive writing isn't necessary, and you do an excellent job of incorporating explanations, but not overdoing it. The style is rather narrative which fits perfectly with the genre and the story itself.
However, some sections do contain more explanations than needed. For example, in Chapter 2, when you described Base G-18, you told the audience about it rather than showing them. If you want to explain the base room-by-room like you did, you may want to add more sensory details to really give your audience an understanding of the setting. By simply listing traits of the base, your audience has no connection with it and it means very little to them. By reading so many descriptions, your audience becomes distracted and loses track of where the story is heading.
Something I suggest you think about while you write is clearly separating some sections. For example, in Chapter 1, you wrote about how Wendy repeated in her head that her father had died, and then in the next paragraph you switched focus on Wendy's grandmother. Although you did set up for it, the long emphasis on Wendy's thoughts make the section about her grandmother and the men at the door seems slightly out of place. Perhaps you could add a small divider to show your audience that you are shifting your focus onto a new event related to the previous one.
I also noticed this a few paragraphs later when you explained that Wendy blacked out. In the paragraph after this, you skipped to where Wendy woke back up. Here, you may also want to add a divider to show your audience that you are focusing on a new event. However, in this case, the section about Wendy after she wakes up could be turned into a separate chapter. Although it is somewhat related to the beginning of the first chapter, it is also stand-alone enough that it could be moved to its own chapter.
You do a great job of introducing the characters and showing the audience who they are and why they are important to the story, but they are generally bland otherwise. You didn't include many personality details, so your audience questions what kinds of people the characters are and how they may react to different scenarios throughout the story. I suggest you incorporate some additional background details on the characters to really give your audience an idea of where the characters came from, and why they act and think the way they do.
Overall, I found your story to be quite entertaining and I can tell that you are very invested in writing it. I thought the plot was original and the characters each had a unique part in the story. Your grammar and writing is very good, and your audience was able to keep up with the events in the story without difficulty. It is nicely written with a consistent pace!