the catalogs are not compatible. what i have done is save all RAW files as DNR and save changes into the files. then give her the files. no catalog. is this the best way?
The Catalog of Lightroom CC cannot be opened with Lightroom 5.
You are following the Correct Approach.
However with Creative Cloud you can use Lightroom 5 and Lightroom CC together.See How to Find and Install Previous Version of Adobe Apps in CC 2015 | Adobe Customer Care Team
I also have LR 5.7.1 on my machine but haven't used it since CC came out. now what?
For future Projects you can create a new catalog in Lightroom 5 on your Computer and share the same with your colleague
Else ask your collogue to upgrade to Lightroom CC/6