A relative of mine is coming to visit, and I would like to bring her to a musical. She speaks English, but at a pretty basic level, so it would have to be more spectacle than substance, and she's only 11, so it also has to be kid friendly. The only thing I've been thinking of is the Lion King, is there anything else I should consider?
Every musical based on a movie that your relative have already seen can be a good choice (Lion King, Aladdin, School of Rock).I was myself a non-English speaker when I fall in love with musical theater.
I was 13 and I listened Les Misérables (TAC). I didn't understand most of the lyrics, but the music was so powerful that I got most of it (and a basic knowledge of the story help a little). The next year, I was listening The Phantom of the Opera and Miss Saigon.
If you're not afraid to spoiled some element of the story, you can also prepare your relative to the some elements of the plot (characters, setting, storyline). Or, pre-translate to your relative some of the catch phrases of the show. For example, If you see Wicked, you can tell her what "Dancing through life", "Defying Gravity" mean (but before the show, because during it's really annoying). Then, during the intermission, you make sure she understood the important point of Act 1. I used to do these things when I bring a non-English speaker to see a musical with me. It's work well with show like Lion King, Shrek, Billy Elliot, Phantom, Wicked,
Maybe I do not speak English as well as you, but I can perfectly pronounce the names of all characters of Les Misérables.
The Radio City Summer Spectacular is non-stop state of the art breath taking special effects that can only be presented at Radio City because of the five stage elevators and enormous stage. Your guest will be amazed. Just seeing the theater is remarkable.
Due to the current script not speaking english may be a plus.
Friend from France visited me who speaks basic English. I took her to Paramour and she loved it!!! Lots of cirque du soleil stuff where English language is not a pre-requisite. The general story is very easy to understand as well.
Four years ago when she visited me, she loved Spider-Man (which is another musical where knowledge of English isn't required to understand the basic story.)
I haven't done it with kids, but I've taken my parents to shows both in London and New York, and they both only speak basic English. My way to go is to see something adapted where they know the source material, or I can tell them to watch the movie beforehand.
I don't see why the same strategy shouldn't work for a child. By that logic you could see Lion King, Aladdin, School of Rock or Matilda. She probably knows both Disney movies already, and if she doesn't know School of Rock and Matilda, just get her the DVD.
If you wanted to see Phantom, perhaps get her the DVD of the movie before to watch. I was pretty young when I saw it (my first musical) and I loved it, so I guess that would work, too. Same probably goes for Les Mis.
I have mixed feelings about Paramour and the Radio City Shows. It just isn't a real Broadway show, and I feel like, when you take someone to their first Broadway show, it should be a real Broadway musical, you know? Not a cirque type show that you might as well see in Vegas, or the Radio City Spectacular, which isn't even on Broadway. Nothing against those shows at all, but I wouldn't want that to be someones very first show...
I don't remember Cats well enough so judge if you could follow without understanding what's being said. And I feel like you would miss too much in Wicked. There are so many productions of that all across the globe, might be easier for her to see it at home, wherever that might be?
Anyway, my top choice for an 11-year old girl would be Matilda!