then she appeared

I think the certificate is a fine idea! You really are way too skilled and way too educated to be doing training occasionally for the odd consultant or two. You really like building lesson plans, and whenever you've talked about your classes, you were very deep in theory without even thinking about it.

I would talk to a career counselor to see if the certificate would be enough. You don't want to take the time if a different course of instruction would serve you better.