@Lucy1217,
ASD is Autism Spectrum Disorder -- it means she is on the autism spectrum (but that can be a wide range).
Among other things, this probably means that she has an IEP (an Individualized Education Program) and that there are people who want to know about her behavior so they can help her modify it if it's inappropriate. They can't help her with stuff they don't know about.
So, yes, say something. And generally, don't feel like you have to put up with that sort of thing, ever.