hmm thats a bit of a tricky one, because you don't want them trying it out of curiosity, and you don't want your daughter feeling bad if they do. Also not a good idea to try and stop your daughter from swimming. I'm no expert in this, but how about something like;
"you know (daughter) has been sick for a while, well she hurt herself while she was sick, and she has some scars from it. She is ok and getting better now though, so don't worry if you see any, ok"
Something like that perhaps? and obviously make sure you answer any questions they have. And as much as it feels you should shelter and protect children, honesty is usually the best policy, as they often find out at least some of the truth for themselves
that was exactly how I dealt with it and to be honest they didn't bat an eyelid.... pity other people aren't so understanding.... whilst she was at work he sleeve rode up a little and a woman saw them and moved her daughter away saying you don't want to catch anything
daughter dealt with it well and I guess its going to be something she will have to deal with