How long could a kid be sent to juvie for trespassing on museum property i proximity to a robbery?

@asklemmy

I’m working on a scene in a book where a 10-year-old girl is arrested right after stealing and handing off the macguffin, but due to good teamwork there is only enough evidence left behind to charge her with trespassing. Considering that it can easily be deduced that she had *something* to do with the stolen macguffin, how long could a judge put her in juvie?