Yes, think of 22-ct. Hardanger as 22-ct. aida. I am sure this is her original stitch. For example, in Mrs. Christensen's book, she has 303 stitches. This is the same as there are no new recipes under the sun.
Stitches are either crosses, straight stitches, knots and other lumps, and loop stitches.
Denise Pratt has a lovely star-type stitch, too. Drawings and descriptions of how to do the stitches are copyrighted, of course. As long as you do your own drawing and description you should be ok. I don't know the scope of your intended project, so you should consult an intellectual property attorney. As to the JoJo stitch, I'd write and ask if it is copyrighted.