RandyAmy, some good info here, some irrelevant and some incorrect.
I'll say, bags are a good option if needed and very reliable setup. There are other suspension enhancements that are more permanent in nature and this less versatile as well.
No idea what is needed without knowing what the camper weighs and even then, the method you use, if you need more suspension is subjective to your preferences.
There are several different ways to shore up a saggy suspension. The common ones are:
Stable loads. Either commercially available or home made.
Air bags. Several levels of strength and versatility.
Add a leafs, several kinds.
Bump stop replacement type springs like Timbrens and Sumo springs
Replacement spring packs or added leafs to factory springs.