I think you're hesitant for good reason on the twitter approach. It would put her in an awkward position. Fact is, she was part of your treatment and it would be unprofessional for her to have direct contact with you.

It sounds like you already expressed your appreciation for the inspiration she gave you in the note you left at discharge, and I expect you also communicated that to her at the walk. I've no doubt that it means a lot to her, truly.

I think it's important for you to recognize where you are in your own recovery, and that your perceptions will change over time. That's not to say her inspiration will be any less potent in the years to come; rather the connection you feel will shift.