When the question is asked, "Can I ever buy a breakable, fragile gift for rvers?" my initial snarky response is "NO!!" But I know that isn't realistic...sometimes perfect gifts are irresistible and simply must be purchased.
So here is my answer (my tips) if you can't resist buying a fragile present:
KEEP IT SMALL
I am sincere with this tip - do not, I repeat, DO NOT buy a set of 8 glass beer steins, all new dishware, a huge set of new corningware. Just don't do it. Making room and safely packing a small thought is one thing, but a huge set of breakable items is another. You can't just let all of these pieces bounce around freely in the rv while traveling down the road. Would YOU want to pack each piece carefully every time you travel? I betcha the answer is no. So be kind to we rvers and if you must buy an rv gift that can break, think small please!
KEEP IT USEFUL
Purchasing a large crystal vase is NOT a good idea, no matter how pretty. RVers have limited shelf and wall space, so figurines aren't practical whatsoever. So what is useful? If the camper on your list loves drinking tea and has always been searching for some antique brand of teacup/saucer...which you happen to find at a thrift shop, THAT is something she would use daily, so it would be worth it and takes up little room. But in general, stay away from things that can't be used frequently.
PROVIDE STORAGE AS PART OF YOUR GIFT
One final tip...you don't want the rver's initial response (not spoken out loud, but in his/her head) to be "how do I travel with this?" So back to the teacup example. Purchase a box that fits the cup inside and have pieces of foam to safely nestle it. When the traveler is packing up to hit the road, he/she won't have to worry or think about it, because your special "safe travel box" is right there.