I still go with my 10 and a half year old and can't see myself stopping anytime soon. Its no difficulty for me to go with her. If I have DS with me then he comes too. She doesn't know why I go with her, she just accepts it as normal because that's how its always been so its not instilling fear in her about what might happen.
There are other ways for her to be independent. I see public toilets as a higher risk than many other activities because they are concealed areas, with places for people to loiter and hide (the cubicles), with reasonably good soundproofing, and once inside there is no alternative exit so there is no escape for a vulnerable child. It doesn't pass my personal risk assessment. As opposed to going to the shops where there are plenty of people around, its easy to run and shout for help if someone scares you, and its very open.