Board Thread:General Discussion/@comment-25028999-20140801192152/@comment-4536113-20141008193834

A theory that I love and read elsewhere is that Rose intentionally gave up her physical form to have Steven be half-gem and half-human. This was done to allow him to bridge the gap between Gem and human kind, as there seems to be an underlying conflict going on there, and being both Gem and human, he'd be the most likely to be able and do what Rose couldn't, which is connecting both species.

I also agree that Rose is likely still in Steven's gem.