So I'mma lay all my cards on the table: I've only seen 6 seasons of SPN.

That said, Linhardt is both really interested in other people's powers and very open about his own magic. So he'd come poke around if/when Rowena makes it known that she has magical powers. He's particularly interested in comparing similar powers, so if she has healing abilities, that's of interest to him.

Boredom is a perfectly valid reason to harass people. Linhardt approves.