It is funny how different we all are. My DM and DDad are certainly very proper and traditional in many ways, and are also now in their 70s, but I still see them naked regularly, when I go and visit. I often sit on their bed and chat, while they have showers and get dressed in the morning. My Ds, who is 11, sees me naked and I do not try to hide things. I do not parade around the house, but he knows that if he comes into our room or bathroom, then it is possible that I will be coming out of the shower and getting dressed, and he may see me or DH undressed. In DH's family, seeing each other naked would be terrible and would never happen
DS keeps his door closed when he showers or gets dressed, and we absolutely allow him that privacy. But I am trying to ensure he grows up without shame of his body. I am also doing my best to talk to him about sex and periods, etc... as I am the only woman in the house and I do not want him to be ignorant of these things. His Dad cannot talk about sex, they would both die, which I find so funny.
I started using tampons at 11 - I was a swimmer and I needed to get into the pool 3-5 times a week. I also remember a vacation in Tuscany, where I was not prepared to miss out on the swimming fun! I do remember me and another friend helping a third with putting her first tampon in. It was in the toilets at school and she could not figure it out. So while this situation is unusual, I do not find it that weird. And by the way, 10 year old girls are very prone to exaggeration! I know my friends and I certainly were!