I may be the only one, but I still believe that the letter is about Regina. I think this whole thing is a fake out. We saw first hand that Rumpel just thought of Zelena as a fly to be played with, and then swatted away. He really showed no interest in her due to her annoyingly obsessive behavior. He had this attitude toward her like “You’re fun and all, but I already have a child to find and raise. Don’t need another one. Shoo.”
So, I’m thinking that this letter was sent to Cora before Rumpel knew that Regina wasn’t Cora’s first born. Thus, there will be a revelation when Rumpel reveals to Regina that the letter really was all about her. Of course she’ll find her inner strength, blah blah.
Anyone else think so?