Okay to submit LOR from continuing education instructor?

[lsgchas]

I'm a non-traditional student who graduated college 15 years ago. I recently received a Certificate of Technical Writing and had a great instructor for one of my courses. She has already agreed to write me a LOR and I think it will be a good one. My certificate was awarded to me by Clemson University, but I only received Continuing Education Units, not college credits. I certainly felt the courses were as rigorous as the undergrad courses I took.

Since this was my most recent educational experience, I'm hoping graduate schools will accept this LOR. Does anyone have any insight into this?

[emmm]

I think it would be more relevant than a letter from someone who had you in class 15+ years ago.