Lots of repetition of 'strength vs intelligence', 'weakness', and 'exploit' started to feel like it's only purpose was to remind us you were doing this to theme. Use different words if you're going to say the same thing, but try to avoid it altogether unless it's required.
You could probably delete the third paragraph entirely as it just repeats the same stuff from the one before it.
Telling us how great a character is can't hold a candle to showing us how awesome they are in the story. While we are constantly told how she is strong and smart, we don't see a lot of real evidence of it in story. The betrayal by a lieutenant felt like 'Oh, and this guy? This guy you weren't even shown before in the script? Well she trusts him, but he sold her out!' Who is this traitor? Why did they do it? HOW did they do it? Did they just straight up stab her literally, or did he move defenders from a spot and let the enemy in? Were they working alone?
I also feel that unless she had some really reliable intel/spies, a lot of the opponents' plans (cut supply lines, starve them out, night raids etc) should have at least done something to her army's morale if even in the temporary. This could have been a stronger tale had some of it worked, as it could have easily reduced her armies numbers, their loyalty resulting in the betrayal, and even made this clash a challenge with Lyra fatigued, half-starved, maybe even a little paranoid...
Even so, I look forward to more. I want to see you grow as a writer cos I think there's something here, so don't give up.