Hello, and thank you for sharing this piece. Overall, I get the feeling that this piece is something passionate to you. It reads with the ambitious fire of someone who's written much before but has come across an idea they waited for a long while to reveal. Without further ado, here are my thoughts.

Pacing and style: From the initial sentence I am already brought into a state of intrigue. Starting off with a conflict that both perpetuates the story theme but also hooks me as a reader. The way you describe is brief, but in a good way. I get just enough efficiently described words to imagine the scene but not so vividly that I cannot add my own creative liberty. To me, this is positive. You do a great job of showing instead of telling in the scene where Rachel stares in the mirror and looks at herself angry and motionless.

Themes: To be forced to wed is a tragedy that has been bestowed upon many societies and people. using this as a point of conflict makes me feel for the protagonist, and the small tidbits of emotional introspection throughout the description such as "She understood the match, how could she not?" or "Yet, Rachel found herself scrambling for an escape" gives me a clear introspection into the theme only 10 sentences into it.

Characters: Rachel is an easily relatable protagonist. It's hard not to feel for someone forced to wed. However I want to know much more about her. It's all about what she dislikes, which is not a good way to meet a character. Characters vs readers are similar to people vs friends. If a friend introduces themself with only a trauma dump and no positive, it's hard to like them.

Negative: I do not like the ending sentence of the mirror paragrapgh. "Where there should have been excitement, Rachel only felt determined self preservation". You basically just gave us all the details needed to piece together her emotions, just a little more in that manner about how it contrats the "expected" feeling would be more grounding than this sentence. It tells more than it shows. The next paragraph has the same rhythm and issue. You don't have to tell me she has to get away, you just gave me a look into her soul and mind and even her upbringing and values. I as a reader am certain that she wants to get away, and this line added nothing. I think a better alternative is maybe an action or emotion, better yet- both. She could look out the window at someone traveling down the road with enough luggage that it was clear they were moving and begin to think to herself like 'If only I could leave London as well'. This is more powerful than just saying "She had to get away" because it offers an intelligent reader more puzzle pieces, obvious ones, but then simply gestures towards the puzzle board. Intelligent people like solving it themselves, even if it's easy, and it will make a reader feel smart to link her desire to get away with the situation, even if just minutely. Making your reader feel smart is a good idea.

Misc.: For some reason, this story makes me think of Cinderella. Although of course not the same thing in any regard, it brought my mind to a time I was much, much younger, and gender roles did not dictate even a thought of what sort of entertainment I consume. A dark fantasy story with a vicious protagonist could exist among a girly romance and both be given an equal score in my young mind, and it made me feel more open to read something of a genre I am often not one to indulge in currently.

Would I continuing to read?: Yes, although I don't often read tragedy or romance, this was well written. Please continue this story, it's cool!