You have decided to further your story along by adding in a fight scene. This is essential to the plot and you need to make sure you nail it so your reader will be on the edge of her seat throughout the passage. How can you make this happen?
Your reader needs to believe that the fight scene is actually happening to your character. Just as the rest of the book needs to make sense in a way your reader can identify with, so too will any physical altercations. This means holding true to the characters you’ve created and the world in which their story is taking place.
If you’ve been working with a character who is small and thin, it doesn’t make sense for her to throw a punch like a prized fighter with three hundred pounds of force behind her fist unless something in the story has caused this to happen. If the laws of gravity don’t apply in the location of the fight, it would be unrealistic for all of the fighting to take place on the ground simply because you are more familiar with fight scenes happening in this manner.
It’s important that you know what could and likely would happen in the scenario you are describing for your reader. Be aware of the injuries characters would likely sustain from the fight, make a point to have background commotion if the fight is taking place in a public area, and be sure to address the adrenaline rushing through your character while she navigates this terrain.
Think about what you can do to convey the situation as best you can to your audience as well. Your character is in a high-pressure situation where she needs to make quick decisions. This means her internal dialogue will likely be short and clipped, and should still hold true to her personality. This will likely also mean shortening your sentences and paragraphs to keep up with the action in the scene so it stays moving at a reasonable pace for your readers and gets them eager to see the outcome.