The OWLS-II is a respectable test for language evaluation. It has two main sections, each divided into two subsections (your DS may/may not have had all of them administered, depending on the referral question): oral language divided into listening comprehension and oral expression, and written language divided into reading comprehension and written expression.
It does have conventional standard scores (x=100, SD=15), as well as test-age/grade equivalents (all usual AE/GE caveats apply).
One of the nice things about this test is that every item is tagged for the aspect of language that it assesses, and many responses can be scored for different aspects of language, in four primary language areas:
lexical/semantic
syntactic
supralinguistic
pragmatic
and also in two others for written language:
text structure
conventions
You wouldn't have standard scores for the above six qualities, but a good examiner should be able to obtain fairly rich clinical information from the item analysis.
Note the specific inclusion of pragmatics. The CELF-5 Metalinguistics test, which is specifically a comprehensive measure of pragmatics, starts at age 9. Probably what she's thinking of. The CELF-5 does have a Pragmatics Profile checklist that generates scaled scores, beginning at age 5. Easily done based on interview and/or (preferably) naturalistic observation. The venerable Social Language Development Test starts at age six.
Is it possible the slp is reporting T scores, rather than standard scores? That would make more sense, as 85 would be +3.5 SD, and thus more likely to be consistent with hitting the ceiling on the test, and attaining an AE of 14-21 years. (14 to 21, I suspect is because some aspects of (probably oral) language plateau in early adolescence). Hospital/clinic-associated evaluators sometimes have specific ways of reporting the scores, which may not match the original form of the z score conversion. It doesn't change the meaning of the scores, but it sometimes facilitates comparisons across instruments. Typical ones are converting everything to standard scores (x=100, SD=15) or T scores (x=50, SD=10). Or sometimes using actual z scores (x=0, SD=1.00).
