Would you call her Elsa-Rose most of the time rather than just Elsa? If so then maybe it would be easier with the hyphen. I do think it's nicer without though.It would be lovely to see Rose used as a first name rather than a middle name :)
ElsaRose all of the time, or at least I'd try, I know quite a few people with hyphenated names but only go by the first one and I just don't see the point. I agree about seeing Rose up the front for once! :)