I think your guide is great, and it provides new players who have less glory to get a solid hero and play her well. I also have a few suggestions/questions.

I was wondering what your reason was for a tension bow in the late game over a second defense item. Tension Bow is very strong early game when it can provide a lot of burst and enemies have less health and armor; as well as being strong on heroes like Gwen or Caine whos passive and abilities works well with it. Well still being viable late-game it might be better for Rona to pick up a situational defense item (Armor or Shield based off of the enemy's builds) because, as you said, Rona can be squishy without her ult and a second defense item would allow her to stay in team-fights longer and build more Breaking Point stacks.

I would also recommend talking about weapon infusion and when you should purchase it, as it can give you a big power-spike in the midgame when you buy it.

Anyway, that's just what came to mind, you can choose to use it as you wish. Have a nice day.