teeth brusher

Is it common for people to brush their teeth at work? I find it so bizarre. Every morning in the ladies room around 9am, it is a guarantee that you will encounter this old woman who I have dubbed the "teeth brusher". It's not a bad thing, she just makes me feel awkward. There is something disturbing to me about brushing teeth in a public bathroom, especially one in DC, where we have a lot of homeless people that like to hang out here. And having a toothbrush and toothpaste to carry could be a burden. My bag is heavy enough. Sheesh.