Naked at times with step sister

I went on holiday with my dad and step mum and half sister, we went south of France, I was about 10, sister about 8, she only used to wear bottoms on the beach, didn't have to worry about a top, most woman were topless anyway. When we went back to the camp site we were staying at her mum (we had the same dad), said to go in the shower with me rather then on her own in the womans , we didn't think anything of it and showered together. we would sleep in the same area in the tent in our sleeping bags, and with it being hot they were normally undone and just over us. After a few days wearing anything at night was to hot so would go bed nude, we would end up just pulling 1 sleeping bag over us together not thinking about being nude. It was one day we were in the shower that I got hard, I had had hard ons before but not in front of her, maybe under the sleeping bag, but it happened in the shower, I couldn't hide it as we both there nude, she was looking and asked why its sticking up, I just laughed it off saying it happens, I was embarrassed, The next day after being on the beach and we went the shower, I got hard straight away, we both just laughed and I didn't hide it., after that it happened every night in the shower, we still shared the sleeping bag and I got hard then as well, but rather then try to hide it I would pull the cover down and lay there. We done this for the 2 weeks holiday. Anyway soon after we got back our dad left her mum and moved in with another woman, I never saw my sister for a few years, then we stayed at my dads house one weekend, I was 12/13 she was 10/11, I was going to have a bath and she came upstairs with me, I said get in as well not thinking anything as we had showered together, she did, then we both just looked at each other, obviously I was hard and had some pubes, she had bumps on top, I had just discovered the joy of wanking by then, so as we in bath together I started wanking, she asked why I'm doing it and I said cause it makes me feel nice, she just watched and never said anything, After that weekend I never saw her for few years and its never been mentioned again, I do often wonder if she remembers it