Zatch Bell might be a pretty good one to watch. I enjoyed it quite a bit as a kid, and rewatching it a few years ago, I still felt that it held up fairly well. No fanservice(it was on Cartoon Network), funny, the female characters don't exist to be objectified, and the violence isn't gory or anything(once again, it was on Cartoon Network). Overall, it seems like it'd be a pretty good show for someone around her age. Unfortunately, the dub ends around halfway through the series, so you'd have to watch the rest in subs online somewhere which may or may not be a problem for her depending on how comfortable she might be watching a show like that.
A fairly recent recommendation would be Barakamon, it being about a calligrapher who get's sent by his dad to live on an island after getting a little to aggressive with a judge for insulting his calligraphy, and the story follows his various interactions with the islanders. No fan-service, a fairly large cast, humorous, plenty of female characters, and no violence.
I might recommend Hidamari Sketch, as it centers around 4-6 non-sexualized female protagonists, and their day to day lives, but that's pretty much all it is. Their day to day lives, and not much else. Very little conflict, no overarching plot really, it's sort of like K-on in that nothing really happens, you just kind of sit back and relax and watch them tackle their daily lives. The only pro here for your sister would be as previously stated, the non-sexualized all female cast that don't spend their time talking about boys either. May as well throw in a vote for K-on as well if this series made the list.
I'd second Gekkan Shoujo Nozaki-kun, but I think it kind of requires somewhat of a prior knowledge of manga/anime tropes for you to really enjoy it to it's full effect, although some might disagree. But for someone who's completely new to anime, it might not be something to immediately check out, but definitely worth checking out later down the road.
That's about all I can think of at the moment. I'm honestly not sure if any of these are really the best choices per-say, but they at least shouldn't contain any fan-service or strong violence. Also worth noting, I'm pretty sure Zatch Bell is the only one of these shows with a dub, so you'd probably have to watch the other ones subbed. Wow though, didn't think finding good anime without fan-service/violence would be this difficult, and this is coming from someone who tries his best to avoid fan-servicey anime.
EDIT: Oh, how could I forget Nichijou!? Very funny, and something I would genuinely recommend to anyone, and it doesn't contain fan-service or strong violence. It may even have a dub too, although I am not 100% sure at the moment. Of all the stuff I've recommended, Nichijou is probably your best bet for a show that meets all the requirements, and is actually something she would probably enjoy.