Giving
Like many on here who feel strongly about transing children I was that non conforming tomboy. I grew up years ago and was generally allowed to get on with it but there are certainly some things that would have made life better in my day. For example, my mates (the boys) all played football for the school. I was way better than them but had to play netball! They all went to Cubs then Scouts and were allowed to have proper adventures, I was stuck with Brownies and refused to go to Guides. I had to wear a swimming costume, which I hated, when I went to the local pool which was completely stupid as I had no boobs and I couldn't wear trousers for the first few years of school.
I believe girls are allowed to be the same as the boys in all those areas now, at least up to a certain age, and that would have been better for me.
I was however allowed to do the 'boyish' things I wanted most of the time. So went fishing and to football with my Father, made camps and had fun with my (boy) friends and never had a doll or toys that were remotely 'girlish'
It sounds like you are doing everything right, just keep going being proud of your daughter for who she is and don't give into any external pressure to force her into any box that she doesn't fit in. Kids only want to change gender when they are not able to be themselves in their born bodies.
I do think the real challenges start at about 10 or 11 but if the foundations are there she is likely to continue being a happy, confident girl for ever.
For the record I grew up to became a really boring adult. I'm straight, married with children and grandchildren. But I'm still likely to get very fiery if anyone suggests I'd look good in a dress or I should wear something pink, YUCK!!!!