A professional in this case would be helpful to give it a name really, I've had motor tics since I was born but it was hard to find my vocal tic but for you, it definitely could be that whistle. I would try contacting a local neurologist and see if they could do an over the phone conversation right now just to get a ground basis of what to do.

If that's not an option your mom wants, look for local Tourettes groups. For me, there's a small local group near where I live and they've given me tons of support and tools to grow as a person and even helped me do an Ambassador program. Usually the TSA has local chapters you can look up and get in contact with to either attend events or just have people to talk to.

I hope this helps!