By all means, take them. And love every minute of it!
Long ago, when we first started out in fiberglass rigs, we gave our almost-grown kids the option "stay home ... or come with us and sleep in a tent." For reasons that escape
me, they usually chose to stay home alone.
However ... now that they are grown, with spouses and kids, they often will meet up with us ... and camp in tents pitched on our site. Sometimes you have to pay extra for the "second camping unit" ... but that's rare.
Most the time, it's perfectly acceptable. I wouldn't call ahead and ask. I'd just "do it and apologize later and offer to pay a little extra."
We give the female members of our tenting group "middle of the night bathroom" privileges. The boys have to use a tree or trek down to the public facilities.
And of course, we've had several "raining cats and dogs" campouts where everyone piled into the Casita
for dinners, naps, etc. Makes for a memorable campout.
When our son was in college ... we'd go visit him and camp nearby. I'm 6 foot 4 inches tall ... he's taller ... and he often ended up crashing with us ... even sleeping in our Liberty Deluxe's queen size bed.
The more the merrier. Sure, it's tight. But the more the merrier.
Our grandkids are still too young for us to take on an extended trip ... but our plans include me sleeping in the trailer while my wife, Pam, sleeps outside in a tent, with the grandkids.
Hey, you wouldn't want them wandering off in the middle of the night. And since I'm too old to sleep on the ground, I volunteered Pam for the job.