J.,
before you try anything, you need to consult with your Pediatrician.
Don't use things willy nilly or experiment with OTC things.
Don't listen to your sister.
Nighttime dryness, can take even up until 7 years old and this is normal.
And some kids are just not there yet.
My daughter, even when she was 7, needed nighttime diapers. AND she had accidents. Once, she even had a dream that she was on the toilet, until she felt herself wet! LOL I didn't make a big deal of it or scold her. Her bladder was not developed yet enough. AND I already had a waterproof bed pad under her... so no fret. The sheets didn't get soiled. I just had her rinse off, and then put on new jammies, and she went back to bed. And sure I helped her. I am her Mom.
Then by the time she was 8 years old, she was fine at night. And able to get up and did attain nighttime dryness.
But until then, like I do with my son, I just explained that her body is still developing.
My son, who is 6, still needs nighttime diapers. No fret. I just explain to him that his body is still developing. And he is potty trained already. He is just not there yet, at night. His body. And he doesn't even know, while sleeping, if he has to pee.
No biggie.
I do NOT listen to others about it. Why? BECAUSE IT IS A PRIVATE personal matter, between me and my child.
I wouldn't think of embarrassing my child, and telling other people about it. It is NONE of their business.
Get a few waterproof bed pads and put it DIRECTLY under her at night.
I have 4 that I got from Amazon. And the sheets never get soiled. I just rotate the bed pads and replace it with a new one. All I have to wash is the bed pad. It being waterproof. A fabric type waterproof bed pad.
I never had to force my kids, to change their clothes if wet. They just did it. Or I helped them.
Then, ALL OF MY daughter's Teachers... from Preschool to Kindergarten to 1st Grade, ALL said unanimously... that kids these ages have accidents. Daytime or nighttime. And it is normal. How do I know? Because, I asked my daughter's Teachers. And they said that kids these ages have accidents or are in sleep diapers, but the parents don't admit it... but they tell the Teachers.
My kids' school, the health room even stocks clean underwear/shorts/t-shirts for the kids that have accidents in school. And the school and the Teacher's make NO big deal about it. They know, the Kindergarten and even 1st grade kids, have accidents. Even my daughter did in school. No biggie. The Teacher just makes no big deal of it. Nor to the parents.
Please don't use medications or natural stuff you don't even know about.
And do not listen to your sister. Just tell her it is NONE of her business.
I never... woke up my child at night and dragged them to the toilet. If so, then they would get lack of sleep.
And for my son, who is 6.... I do change his diaper at night, once. Sometimes.
Because, even the Huggies Overnight diapers, if too full, will leak. Although it does hold a lot.
My son doesn't wake.
I go back to sleep just fine.
And there is the waterproof bed pad under him. Too.
It doesn't bother me.
Per your daughter saying she doesn't want her nighttime diaper... well my daughter said that too when she was younger. And again, I just explained to her, that her body is still developing. And she completely understood.
And FYI: pull ups leak. They don't hold much.
That is why I use/used the Huggies Overnight diapers, instead.
And pull-ups, at least here in my State, costs more.