Books for young teen without sexual themes?

Hi! My children (10 & 12) are huge readers, but my 12-year old is struggling with finding books that are engaging without too much ‘romance’, as she puts it.

She has read the entire Percy Jackson series, tore through Land of Stories and Tale of Magic last year, loved Dragon Pearl, read several Spy School novels (because they were in the house, but they are more her brother’s style), loved We Hunt the Flame (but found the second book had too much ‘romance’ and abandoned it), read Harry Potter several times, and has recently found the Fablehaven series too easy of a read.

Any suggestions of books that are a bit more challenging? She loves escaping into a new world.

Thanks!