Random question I know it's early for my daughter but for the future how do I break her from her thumb sucking when it's time?

https://www.tiktok.com/t/ZPRveTX4u/

When she is ready when will stop. I sucked my fingers for 12yrs. It's a soothing thing and if she needs it when she's older it's better than her chewing her nails. That is also how you will know she is tired when she is like 4 or 5 because she will suck and then you can put her to bed. I wouldn't put anything on her thumb bc she could get it in her eyes when she is sleeping

It’s old school but I started sucking my thumb when I was about 3/4 after having a dummy taken away from me and my mum would run a cotton bud soaked in nail varnish remover over my nails right before I went to bed 😂 might not be common practice now but it worked for me when I was younger!
My older sister sucked her fingers as a child and nothing was done about it and 30 years later she still does it and has knackered her front teeth from it!