I'm not sure this is low confidence, to be fair. You've got quite the list of ambitions! Starting a business is hard work, it usually takes a LOT of effort in the early years, and that'll double down for you because you don't want to do something that you've got experience in or connections in already. The only "upside" is that it's likely to be cheap and it is flexible, depending on what you choose. You couldn't choose your own hours to be a childminder, for example, and I'm self-employed but have to be available when my clients need me, on the days they need me.
I'd also really heavily recommend only starting a business in something that you're genuinely interested in, and not just because it pays well or the hours suit, because it's an absolute grind at times. It's been a lot harder than being employed sometimes. There's huge upsides too and I'd probably be a terrible employee now, but since having my children, it's been really, really hard to give it the attention that it needs constantly, and not constantly to feel that I'm juggling everything awfully - because it's all reliant on me, so if it falls apart, it's me that has to fix it/suffer.
I think you'll either get the flexibility that you're after or the pay, for a little while at least.
If you love children, you've got some options there - school work, working at a tutor place, buying a children's playgroup type franchise, working in a nursery, opening as a childminder. There are various degrees of pay and flexibility in those.
I know someone who has three kids and is a part time project lead. She makes good money for it and only works 9am - 4pm, then she's totally uncontactable to focus on her children, but she's good at her job when she's there - and she is available those same three days every week.