We started moving at 10 months and by 12 months mostly used a sippy cup.

I woukd say yes you can definately give silly cup and I’ve never formula fed only breastfed. So all my children had a zippy choice drinking water from 12 months though onwards.

I think you can give the sippy cup and try and see if it works.

My GP suggested no bottles as then it’s another thing to wean them off – I breastfed so they went from boob to sippy cup. There are ones for 4 and 6mths on the market

My boys refused to take to a sippy cup until 11-12 months of age. But once they did, bottles were out the door immediately
Use both water and milk, or which ever you deem fit

You can introduce now. You can use for water only if you want to keep feeding milk from a bottle. As she gets used to it, she may not want to bottle anymore.

I don’t think it really matters. If you’re using for milk, just make sure the sippy cup you use can be washed well. I introduced a sippy cup for water for my daughter at 6 months. She took to it straight away and it’s good to get them used to water and into the habit of drinking water. Nuby sippy cups are excellent.