I did this. I left my job and became freelance because I just couldn't be a good mum and good at my job. One was always losing out and I felt stressed all the time and was always rushing from one thing to the next.
I've been freelance for three years now, and there are times when my work comes first, but I have been careful to plan work around my family and not the other way round. Both my children are at primary school now, so I work during school hours and am then free to collect them from school, take them to their clubs and spend time with them every single day.
In the holidays it is a little more difficult, but I plan ahead, use a holiday club for a couple of days and then have free time on other days. Sometimes I'll work while they are at home - again I plan it so that they have something to keep them occupied if I have a call to make or need to concentrate on something. But, I am lucky that my profession allows me to work from home most of the time.
Financially, things are definitely tighter. We haven't made the improvements to the house we wanted to do. I haven't changed my car for over seven years. But, we spend the money we have on what we want. Our bills are always covered, and extra tends to go on holidays (mostly in the UK, often camping), clubs and activities for the children and spending as much time with family and friends as we can.
My take on life is very much that at the end, it's not the size or beauty of the house we lived in, nor the car we drove that matters, but the memories we have - the things that we did and the people we were with.
I was worried about my career suffering. But, keeping my hand in by working for myself has ensured that my skills are up to date and I have more varied experience than if I had stuck working for the same company. For me it has worked out well. But, I'm a few years down the road now. I remember it being a very, very difficult decision to make, and for a whole year I was on the verge of returning to a full time job with a proper salary.
I don't think I'll remain self employed forever, maybe when they are older I will think about returning to a bigger company. But for now, I'm happy as I am.