What a great discussion this has been!
There are nuggets of wisdom in each post here. A few thoughts came to mind as I read this. First, age makes such a difference when it comes to "listening" in on a sibling's school. When dc are young, listening in on portions of each other's guides may not be such a big deal. However, it is important to keep in mind that "listening in" is not the same as truly being responsible for all that is in that guide. The thought process that seems to follow a year like this is "my younger child listened in on my older child's guide last year and 'tagged along', so this year I'll just combine them because my younger child did most of that guide last year anyway". This line of thinking is one to watch out for - the younger child truly did not do the guide just because they listened to mom read some books.
So, if you are going to choose to let your younger child listen in on some of the readings, just be sure that you are both going to be fine doing those readings together again when the child is actually the age where he/she can do that entire guide, each and every box, because it will be at that point that this child truly needs to be responsible for learning those skills himself/herself.
When dc are at an older age, listening in on each other's guides can often cause their school day to be far too long because their guide is already quite meaty. Older dc doing all of their own guide and listening in on much of their younger sibling's guide often do not have the time nor the energy to focus their attention on the work that they should be putting their all into for their own guide. Charlotte Mason advocated dc be responsible for their own reading at the age of 9 yo, or shortly after if they are not quite ready for it at age 9. When older dc are spending a good portion of their day just listening to others read, they do not have the time to truly develop their own skills of reading and comprehending well independently. I will often have my older ds working at a table near my middle ds and me when we are reading his PHFHG's books on the couch. Likewise, both my middle and older sons are working within earshot when I am reading my youngest ds's Thorton Burgess books in LHFHG. I hear them laugh once and awhile at the appropriate places and know they are somewhat listening in, but they are not sitting right by us on the couch - they are continuing with their own guide's work, which leads me to the next thought I had.
The child who is actually supposed to be responsible for the work within the guide needs to be the only one doing the follow-ups with us as teachers. This child should be the only one answering discussion questions, narrating, responding to the readings, etc. When other dc (especially older dc) jump in and answer the questions, this detracts from the learning of the child who really needs to be doing the thinking for that guide. Some of the follow-ups in the guides are based on sharing Godly character traits, and struggles and temptations dc have with those traits. We have found it crucial to discuss these types of follow-up questions alone with each of our dc, even going so far as to be sure other dc are not even within earshot. Sometimes the presence of an older sibling makes a younger sibling feel inadequate, especially when it comes to narrating or answering questions, as they know the older child is probably better at it. So, it is important the child who is doing the guide is responsible for all of the work in the guide - even the oral work - and that this child feels confident and free to share his/her private thoughts or responses to the material. This becomes more and more important as dc grow older and mature.
One last thought is that it is important for dc to develop some independence, and this starts at a young age. Even 2 yo dc should be taught to have some independent activities, even if it is just for 20 minutes.
It is healthy for dc to develop some independent times throughout the day, as this teaches many life skills - choosing what to do with free time, working on something on their own, organizing their playtime, cleaning up their play/work area when they are done, etc. This develops interests and hobbies, and it also defrays the constant question "Mom, what do I do next?"
Dc that have learned to have some independence early on don't need to constantly be told what to do next - they have things they WANT to do next, that they are dying to have the free time to do next, and they have that thought because they have developed that skill through years of having at least a portion of time in their day they are independent for. So, whether your young dc listen in on portions of your older dc's school or not, having some time where they play independently within their day is good. It is also important to have some time in the day when you are alone with each child, so that child feels special and feels open to share personal things. We have found the Bible devotionals and Bible studies in HOD, as well as the character trait type questions to be excellent times to use for this "special" time.
So, in conclusion, younger dc listening in on older dc's readings when both dc are quite young probably is fine as long as this time is NOT counted as the younger child's school time within that guide, as long as the older child is responsible for the follow-ups, and as long as the older child has some time with you alone to really "shine" or to really feel free to "get personal".
I would not personally have older dc listening in on each other's readings, for the reasons already mentioned. HTH as you ponder what you want to do in your home!
In Christ,
Julie
My daughters are the same age difference and love to be together. Maybe a year from now my little one will not be as interested in big sister's activities (she's sort of too young to play on the computer by herself at 3 - she can't use the mouse).