I guess I could be that person. I think what is important is that she NOT talk loud enough for everyone to hear. She could be asked to whisper rather than talk aloud. Give it a try. I sing all the time too, and I refuse to stop that. I just try to keep it to myself.....yes, that's the ticket....keep it to yourself......and not clutter other's airspace.

I have learned and so no one is too old to learn to "keep it in their own space"........

Hope this helps.

P. S. A gentle conversation always starts things out on good footing, so I suggest a gentle, private conversation, asking her in a very polite way.

P. S. S. The alternative is for you to get ear plugs.