This was DD's profile for many years, too. As far as we've been able to tell, her written expression isn't the result of anything in particular save her asynchronous development (well, okay-- possible connective tissue disorder limiting hand stability for WRITING).
Her writing is PROGRESSING nicely, but is still about on par with "about what the bright 18yo is capable of" which makes it appear to be an area of "weakness" relative to the rest of her profile as a student/individual. Her reading skills are well beyond that and have been more or less static for at least 4-5y.
Language arts was a nightmare during elementary, and even worse (if anything) during middle school.
The reading levels were years and years below her needs, and the writing level was... well, at times it was a complete struggle, and at the same time, the motivation to write didn't exist, either-- because, see, the reading selections weren't compelling or on-level for her.
It was maddening.
Keyboarding skills definitely helped. Additional afterschooling in reading helped. It was strategic on our part to frame Language Arts instruction as "writing" class. Because that was the purpose of that course.
So I want to reassure you that in an EG/PG child, it's possible that with keyboarding introduced into the picture, this is still just asynchronous development and not something 2e.
As time has gone on, the gap has closed as literacy skills become about other ideas, and not about "reading" or "writing" in particular.
