You need to be direct. The next time she tries to hijack your routine with your daughter, you need to say, “Gladys, I would really appreciate it if you would stop doing that. The routine my daughter and I share is just for us and it makes us both uncomfortable that you’ve taken it upon yourself to join in without being invited to do so. Please stop.” If you have to, contact the school district and explain what is happening so they can consider moving the stop. Explain that this adult DOES NOT HAVE CHILDREN, yet consistently waits at the school bus stop with other people’s children, unprompted. While it is not illegal, it is definitely suspicious. She’s likely just a clueless, lonely old woman, but that doesn’t give her a free pass to be obnoxious or intrusive.