So, I've been thinking about this a bit. How about presenting it something like this:
"Querida mio, I grew up camping, and would like my children to camp as well because a lot of really special memories for me come from that, but I know that it's not something that was part of your life, and you may not be happy in a tent with all the bugs and bears and things--I thought getting an Airstream would be a good way to make both of us happy. There's this thing they call "glamping"...glamorous camping!"
Then show her all of the STUFF there is online about
glamping. And enlist some of the Silver Sisters to help you in your quest! They look like a fine bunch and surely she can make some friends among them. (And if she does, don't be surprised when s
he takes off in the AS without
you!)