I can't speak to the idea of gradual change, because I've never experienced it. I tend to do change whole hog, like everything else in my life. If I need to do something to continue living (or to start living) I'm not going to do it half-heartedly or with trepidation. I might have to follow steps, but my friends and loved ones, to the degree I can trust them, are WELCOME to follow me through this transition and EVERY OTHER transition major and minor in my life. It's what we do.
For example, my friends and colleagues at work did see me becoming more feminine in my dress and mannerisms for a few months before I couldn't take it any longer, joyfully came out to my whole company, and started presenting fully as female in every way from the very next day, for ever more. It was never a problem, except that it was confusing people when I was still nominally male but would be mistaken for a woman. By the way, I transitioned at 45 and was on hormones for 6 weeks only before I began living my life 24/7 my way. So its not like ANYTHING had changed about my body, except my confidence in my own skin. It was enough to change EVERYTHING.
My family, I honored by coming out to them before I did to the world. They started using my new name and pronouns from day one, immediately. I started dressing when I was with them as often as I could - who you going to practice on and get honest feedback from? They would have given me the same feedback, and watched me go through similar developments, if I had gone through puberty as a girl the first time, so what's the big challenge? Does ANYONE think a 25 year old woman is the same person she was when she was an 8 year old girl? Families adjust to gradual changes ALL THE TIME. Its what they were designed to do. And in my case, they are also great for handling surprises.
What I can tell you, which goes for everyone in your life, if you are able to make a change or announcement and stick to it, it helps them a ton. If you are female, give them a name and pronouns to start using IMMEDIATELY, and present as female as is safe to do whenever you are around them. It is a matter of respect, when you ask someone to start seeing you in a new way, to actually start - at least with them - presenting to them in that new way. That's all it takes. People are pretty fantastic, some more than others.