I have all of these same issues with my 4 under age of 13.
Our issues are also added with some strange plumbing in our house - one of the upstairs bathrooms has a drain line that makes a 90 degree turn at some point in the ceiling. Discovered this with the ceiling opened up during our kitchen reno. There wasn't an apparent need to run the line this way either.
For some reason, the master toilet never seems to clog but the other 3 in our house do.
Our issues are also added with some strange plumbing in our house - one of the upstairs bathrooms has a drain line that makes a 90 degree turn at some point in the ceiling. Discovered this with the ceiling opened up during our kitchen reno. There wasn't an apparent need to run the line this way either.
For some reason, the master toilet never seems to clog but the other 3 in our house do.