User blog comment:Questionsarereal/Is ruby the next Maiden?/@comment-4010415-20180319200031

They never said Grimm killed Summer. In fact, they've never mentioned who killed her, if she really was killed. It's actually very likely that one of Salem's subordinates killed her, considering Hazel outright stated that they've "dealt with" Silver-Eyed Warriors before. Summer had silver eyes like Ruby, according to Qrow.