Fluoride? Please help!

My daughter is 6 months old and has 2 teeth. I’ve been just using water and a wash cloth to wipe her mouth out every day. I’ve been wanting to get a little toothbrush but just haven’t yet. Her pediatrician said at 6 months she should be using a fluoride toothpaste or taking a fluoride supplement and that she did it with her daughter. She said if she doesn’t ingest fluoride then her teeth wont have enough enamel built up when they erupt and her teeth might start to decay. My sister in law has 3 kids and didn’t give fluoride until they were 2 my other sister in law has two kids that are 3 and 5 and still doesn’t give them fluoride. None of my nephews or nieces have had any dental problems. I didn’t think you were supposed to give fluoride that young. I’ve tried to google it but everything contradicts itself. So I wanna hear from actual moms what they think or do for their kids. I’m a first time mom and I have no idea. She’s formula fed also if that helps. I know babies can get some fluoride from breast milk. And we use boiled water for her formula. Should I start giving fluoride? Do the benefits outweigh the risks?