I think the only way to manage teaching and a young family is to work part time. I qualified in my 20s, so buy the time I had children was top of payscale. This meant I could afford to work part time. Yes, there are drawbacks, but there are benefits too...
Apart from inset days, when the children are off you are off to. So generally speaking, little childcare costs. My children have never gone to a holiday club, for example - something they feel most put out by!
In secondary, a lot of the work can be done at home. So when I finish teaching at 2pm, I've left by 2:30 and take my work home with me. I don't need to stay at the office until 5pm to get my work done. I understand this is very different in primary though.
If you're part time, you can have timetables to enable you to be at the school gates. For example, when my DC were little, I worked 9 - 12 every day. This meant that I was able to do every pick up. You can also use your free periods to the same effect. I'm full time now, but due to my timetable I am able to drop my daughter off at school two mornings, pick up two afternoons, and DH does the other day. Between DH, my parents (who pick up twice a week for me) and my work, I don't use any paid childcare. In fact, I only need my parents to provide 1.5 hours of after school care twice a week.
You can change your timetable every year to meet the changing needs of your children. So when my children were in preschool, I did longer days, but when they started school I did more days a week, but worked hours within the school day. I was able to change this to meet my children's needs.
However, a lot if this comes from having previously "done my time" and proved myself. My bosses know I work darned hard, and always do my best. I try to be flexible and work with them to meet their and my needs. So, I get a lot more back from my boss, they let me take my free periods to pick up my children, or to come in late when I drop my daughter at school. It also varies school to school - not all bosses are quite so accommodating!