User blog comment:KressKross/Does Weiss actually sing?/@comment-3146930-20140806031006/@comment-11188061-20140806033321

We don't know what age Weiss is when she sings, and how often she does it, and even the type of audience. If we assume that she's 15 or 16 at the time, then 1 year of hiatus makes sense that no many people will recognize her. She seems to sing classic, and so with exception the Ren and Blake - both seems to have reasons as to why they won't recognize her - I don't think anyone will recognize her as a singer.

Penny might know her, since we're already half assumed that she's a cyborg or android. If she can recognize Blake as a Faunu on first sight that this is very likely.