Written narrations question

Hi!  I have a question about written narrations.  We follow CM in all areas except grammar, writing, and math.  We use BJU English (grammar & writing) and BJU math.  We do copywork, dictation, etc the CM way.  Writing is my weakest area in teaching and I was much more comfortable going this route for this subject. 

This past school year, I had my daughter, who is 10 and in the 4th grade, to do one written narration per week on her independent assigned reading.  She did well with those.  We also keep a history/timeline notebook and science notebook which she does and is what I guess would be considered written narrations in. 

I have read on several posts on this board that most people seem to start with 1 written narration in the 4th grade and increase by 1 per year after that (2 in 5th grade, 3 in 6th grade, etc).  

My question is since we do “written narration” in history and science, and we are covering writing in BJU, do I really need to have her to do any written narrations?  We still do oral narrations.  I just don’t want to overwhelm her with writing.  

Or, should we add in something like a story starter book?  I guess that I am trying to decide how she is going to get in some original writing?  Maybe journaling?

What do you think?

Thanks so much for any help that you can give.  

Christy