I personally think a big family is something like six or more children, but most references I see these days consider three children and up to be a “big” family, so for today these ideas apply to any of you with three or more children to teach!
First of all, I think it is necessary to think about Steiner’s groupings of childhood development, and get away from the “one grade for one age” used in a school setting. So, in line with this, think about grouping your children by development:
In your head, divide your children between “Early Years” and above age seven.
In your head, divide your children in your between those aged over seven but under age ten.
In your head, divide your children between those over ten and under twelve and those over twelve and under age sixteen/seventeen.
These divisions mark the “changes” that one hears so much about in Waldorf Education and parenting – six/seven change. nine year change, twelve year change and sixteen/seventeen year old change.
Hopefully by dividing your children into these groupings, you will start to see how many “main lesson topics” you really have to teach. So, ALL the children in the group under 9 but past the six/seven year change could be in the same group and have the same lessons – yes, for example, your first grader can hear Old Testament stories! I have heard numerous Waldorf Educators, including Rainbow Rosenbloom of Live Education and others, speak on this at conferences when they speak of their time teaching children of multiple ages in one group. These stories will speak most STRONGLY to those of the “proper” age, but it does not mean younger children cannot hear them and draw or paint or model. Of course, the “academic” and “artistic” level would have to be adjusted up or down.
If you have children all of one age grouping but one just on the cusp of turning into another age grouping, I have a few suggestions. For example, if all of your children are Early Years, the rest are ages seven to nine and then you have one who is ten years old, I could see an Early Years time, an ages seven to nine time that could mainly include your fourth grader and then just a few blocks or practice times that would be separate for your fourth grader – introduction to fractions may be one, perhaps you would want to bring Norse Mythology separately. I think something like “Man and Animal” could be mainly brought to your fourth grader, but certainly smaller children will enjoy watching and drawing birds, having poetry about different animals, stories about animals and working on artistic and other skills in this way. You could also choose to make something like Norse Mythology the very last block of the year, if you have, for example a third grader who will be entering fourth grade in the fall and your fourth grader is coming to the end of the school year. That could also work with something like Old Testament stories.
If you have a child above age twelve and the rest of the children are younger, then I think you are going to have to run a separate track for the older child. I find these upper grades to be a different ball of wax. You are really out of mythology land and into history and cause and effect and different capacities.
I hope that helps. There are many Waldorf consultants out there with whom I am sure you could talk with who could give you even more ideas than what I have mentioned here. You really can bring Waldorf homeschooling to all of your children, but I think you must start grouping the children and teaching economically. You can embrace the joys of the home – you are not to create a Waldorf School in your home, but instead to create your home life and adapt the Waldorf curriculum for your home with developmental reasoning. Understand the “why’s” and development behind the curriculum and you will be able to do this!