Perhaps a useful way to think of this is that your daughter is nearly potty trained. It's not unusual for such a pattern to occur - it's not as if one day a child is not potty trained and the next day the child is potty trained. It's a process that evolves gradually. If the policy of the camp is to use diapers in such a situation, let it be. It's OK for you not to employ diapers at home.
SimplySimply sleep explain the situation to your daughter - i.e., that at camp it's not convenient to be managing the laundry, clothing, etc. occasioned by accidents, so diapers make the situation easier to handle. But that at home you want to continue to help her with potty training, so don't want to return to diapers. Don't worry if there are different practices in the two settings. It'll be OK.
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FOR ALL THE LISTENERS OUT THERE!!!
START POTTYTRAINING EARLY , AND THEY WILL LEARN IT FASTER. MY CHILD IS 15 MONTHS OLD AND STARTED POTTY TRAINING HER AT ONE YEAR. I SAW THE PATTERN SHE WAS IN AND JUST PUT HER ON THE POTTY ONE DAY. NO I DON'T EXPECT HER TO DO IT. OR EVEN TO GO ON HER OWN. BUT SHE WILL BE FAMILIAR WITH IT AND NOT SCARED OF IT. THE YOUNGER THE BETTER. DON'T TEACH YOUR CHILD TO WEAR A DIAPER. TEACH THEM BOTH AND THEY WILL EVENTUALLY LIKE THE POTTY BETTER. NOW MAGGIE GOES TO THE POTTY EVERYTIME SHE IS SAT ON IT.
SHE CAN'T TOTALLY WALK YET BUT SHE CAN POTTY !!LOL