I have e-commerce extension activated in library named "adobe". And I create tags in library named "marketing". I do not have access to push changes to Main Profile or I cannot go to Main Profile and do testing. E-commerce extension can be created or activated only once. Main profile inherits e-commerce extension from the library "adobe". But I would like to test if e-commerce data elements are called for tags from marketing library, then how to do?
So, @jsmacys, you have a parent profile (which Tealium calls "Library") and then you have a child profile which inherits from the parent? Your 'Marketing' profile inherits from 'Adobe' profile? If so, and as it seems you have the E-commerce extension in parent profile you don't have to worry about data not being set. The parent and the child will work like one profile, only that you cannot edit the parent from the child.
Not totally sure what you mean with 'Main' profile, but it sounds it inherits from parent. If you cannot edit and publish in parent/Main you cannot test it unless you point to just parent profile in your code - but would not be very realistic and not recommendable. So either someone else has to do the publishing and they you can test it as described below. Or, you need to get access to publishing. I guess you have a test or QA environment, which would be enough for this.
Once the E-commerce extension is mapped properly it will produce populated data variables if the source is working. Easiest and low-tekkie is to use Tealium Web Companion. Go to 'Data' and then 'Universal Data Object' and you will find every E-commerce extension variable listed with current values.