What you do is allow her to learn from her mistakes.
I told my girl over and over and over and over and over to wear a heavy coat, it's winter. She would wander out in a hoodie or a sweater or jacket. I'd sit and wait and make her go change.
One day I'd had enough. Love and Logic tells us that kids will learn their lesson much quicker if they're allowed to make mistakes, suffer the consequences of their own choice, and we stay out of it.
So we were heading to BMX one day and I remind her it's bitterly cold out. I told her to make sure to get her heavy gloves and hat, it will be very very cold on top of the hill.
She came out in her racing pants and shirt, they're thin fabric, stretchy and they wick away sweat. The pants had leather at the knees and a few other places and they're double thick some places too. But her body, for the most part, is encased in a light weight denim jacket.
I shut my mouth and let her wear it. I figure even if she gets sick she will learn what it is to feel cold.
We went to the track. Warm ups came and went. When she's riding she wasn't cold. When she was waiting she was shivering. Then we took a break for a few minutes to set up the motos. One of our friends had a tent set up with a kerosene heater going inside. I let her go inside, I truly didn't want her sick, I just wanted her to feel the cold and suffer a little bit so she'd understand what it is to not dress warmly in winter.
They were all "Let me give you my coat" and I told them she had been told plenty of times to get a coat and that denim jacket was what she choose. I told the parents what I was trying to do. They said more kids needed to learn consequences for their actions.
So she spent about 3 hours running out of a tent where it was toasty warm to her bike, then she'd ride her race, then run back to the tent.
She wore a coat every single day after that and I didn't have to tell her once to go get it.
She's older now and can make that choice on her own. She comes and snuggles up to me and sort of crawls inside my coat. She had me buy her a coat of her own choosing the other night so now she's wearing a coat again.
I think you need to let her choose what she wants to wear. I do think you need to keep safety measures in your possession in case she does get too much beyond what her body can handle but she does need to get bone cold so she can understand what you've been telling her.
If we constantly tell them they are going to freeze to death if they don't put a coat on then when they go out and they don't freeze to death, well, that makes us liars and they don't have to pay us any attention. We are obviously just not trustworthy.
But if they do go outside and get really really really cold and we don't rescue them, that's when they learn that mom was right.