This is such a common feeling! I can't tell you how much I thought about home ed before I actually did it, or what a monumental decision it seemed when I finally and tentatively took DD2 out of school at 8. I actually told everyone it might only be a few weeks and I was sure she'd be back - I was so terrified of thinking of it as a permanent step.
Over 3 years on and DD2 is 11 and now too old to go back to primary - and it finally feels like a permanent step. I'm finally happy to tell people that and not feel I am keeping my options open.
Someone said to me when I was having your dilemma, "choosing means losing", and it's true. Whatever path you take, there will be things on the other path you'll miss. I was worried because it was autumn term that DD would miss all the lovely Christmas stuff, school photo, school disco, and the clubs she did at school. I kept dithering and dithering. In the end I told myself we would try it, and if she missed it we would go back. We were lucky in that I knew the school had places.
And in the end, yes she has missed out on those things. But so many things have replaced them, wonderful stuff she'd never have done if she was in school.
Last summer, we talked about her going back to school for the last term of Y6, to get a sort of closure. But in the end she couldn't do it because of all the home ed stuff she'd have to miss or give up! I never thought that would happen.
A year later my elder daughter came out of secondary school, at the end of Y7. That was a truly terrifying leap in the dark, I can tell you. But it was only once I started looking at what she'd been learning at school in detail that I realised what a monumental waste of her time much of it was. She's now Y10 and absolutely thriving, academically and socially. She has so much more self assurance and confidence than she ever did at school.
I could go on and bore you for ages....but what I will say is that only you can decide. Trying it will always be a scary decision. But I told myself that it's usually the things you don't do you regret, not those you do, and I took the leap. You could always start with the child you think would benefit the most/ is keenest to do it and go from there.