Tell them that anda enjoy it, and just because they don't watch it doesn't mean it sucks.Most anime actually have interesting plot, characters, and amazing art. It's okay for her to dislike it, but telling people who like it that they have no life is just going too far. If your "friend" still thinks anda have no life after anda tell her this, well, then she's probably not a true friend.
Tell your friend that "(Insert her favorit tampil here) sucks, and people who watch it have no life." When your friend responds oleh saying that you're mean and don't know what your talking about, respond with: "Then why did anda say the same thing about anime?"
Honestly I would tell them to shove it. I would also counter her bad insult oleh insulting one of her favorit things and after she's really offended I would stop being her friend because if someone does that they are not friends. And the only reason why I would insult is to give her a piece of her own medicine. That girl is an idiot and anda probably should stop being friends with her.