Silver

Silver (voiced by Rachel Bloom) is the speedster sister of Chuck and Red's love interest. She’s a young rock musician, vlogger and brainiac interested in science who doesn’t let her opinions be compromised by, in essence, a character that is always trying to mansplain her and who is threatened by her. However, despite being Chuck's younger sibling, he still sees her as nothing but his little sister and it is a role she’s trying to get away from for a long time.