So, Rowena is pretty much canon, passionate, loudmouthed, the whole nine yards. EXCEPT, she is now in the Department of Magical Gaming and Sports, working under the Head.
So, I imagine Rowena ignores the fact that Perry is ridiculously hot, and focuses on his douchiness, which would be hard, but she's Rowena, she can do it. I do imagine her getting pissed off at the mere sight of him/D. Malfoy at school, and since she's only a tad more mature than she was, it's only a bit--so she still scowls and rolls her eyes, but tries to be civil for the sake of being civil.
I really think it would interesting to see them interact, not to mention humorous.