Hal 9000 said:
For the Leia training flashback, Leia’s face displays some emotion so I don’t think it would fit to just say she decided to go with her political career; there should be something there but I’m not sure what. >I honestly don’t see any problems. She knows being a jedi means a great deal to Luke, to her father’s legacy and to the galaxy overall, so it would be very natural and expected that she’d had some massive inner conflict about “abandoning” the jedi path to follow a political career.
+1 to all this
While that would work better in terms of sentence structure, I believe the goal here was to replicate his style of introducing lessons from TLJ.
“Lesson one. The Force is not a power you have…”
“Lesson two. Now that they’re extinct, the Jedi are romanticized, deified…”
In that context, I think the line might read better as:
Luke: “Rey, lesson three. Some things are stronger than blood.”
I also don’t necessarily want him to use the word “three” because those three lessons were about why the Jedi ought to end. This lesson is encouraging her to be a Jedi.