So are you saying children shouldn't be in trailers, ie trailers are somehow more dangerous than merely cycling, and if so, why? Or are you saying cycling is too dangerous to involve children in at all ?
Well since you ask...
To my mind you put kids in a trailer so they get hit by the following traffic first, you can't see them to look out for them. And they have no control to enable them to get out of the way
In other words they are sitting ducks
If they were on their own bikes they could be in front where you could see them and help or advise them
And I could be wrong but trailer seem to be made of Kleenex and spit, so offer no protection whatsoever, a car wouldn't be allowed to be built with that level of passenger safety so why put your kids in one.
But as I said its the OPs choice as its the OPs kids