rge- I have just spent the last minute of my life saying Elowen and Rowan every way I can think of... yelling, really fast, slowly, etc. So now that my fiancé thinks I am INSANE, I will say that I don't think they would cause too much confusion. Other than you and your husband, how many people will say their names together?
I like it. I don't mind matchiness in siblings. Elowen FEELS like a sibling to Rowan... does that make sense?