You’ve seen the reactions here o/p, and the particular brand of cuntynish that this subject evokes.
It may well be that your sister has been listening to this shit and feels like a shit parent for having stupid thick children that she can’t parent well enough to “train” to not piss their beds.
If she has this may well be an attempt to do what so many posters are saying, to force them into being dry, to “teach”’them that pissy beds aren’t nice, as if somehow just removing the nappies and allowing them to wet the bed will make them learn not to produce night time urine and to wake up if they need a pee.
I have known people who wash two sets of piss soaked bedding every day, rather than use nappies, for years. Because nappies/pull ups are babyish, lazy, they won’t learn... and if they’re not wearing nappies at night, you don’t have to admit to yourself or anyone that your 7 year old is in nappies at night, because technically, they’re not.
Mini that sound like hard work. I am suprised an enuresis clinic (is it nhs?) would do all that with a 6yo, as it’s not classed medically as an issue til at least 8. Won’t make any difference anyway, until her pituitary starts producing adh, and no amounts of alarms will make that happen. And not doing all that is not parental laziness, btw.