Board Thread:Speculation House/@comment-76.110.43.186-20160608215416/@comment-4010415-20160608232203

The most important thing to consider is that the RWBY crew have told us a few times now that Cinder is not much older than the Beacon students, so she's in her early 20s at the most.

Considering Summer died when Ruby and Yang were little kids, that means Cinder was just a child when Summer died.

Therefore, Cinder could not have killed Summer.

However, I wouldn't be surprised if Summer was murdered.