Here's what I would do.
Make sure the dump valves are closed. Don't pull them open yet, just push in and make sure they are closed.
Take the dump cap off on the outside and leave it off to check for leaks.
Before you try to flush the toilet add about a cup of water to the bowl and let is sit for a few hours.This will hopefully get down between the bowl and seal and lubricate the seal to prevent tearing. See if the bowl leaks down.
If no leak down then open the flush valve and pour about 5 gallons of only water into the tank. Wait for a few hours and see if water starts dripping out of the dump hose.
If it leaks there is no sewage to hamper your repair efforts, just water. Rebuilding a leaky dump valve will cost you about thirteen dollars and take you maybe 10 minutes.
Providing all is well you can add whatever chemical you like,from Walmart. Personally I don't use chemicals and there is no smell when using the bathroom.
Use whatever toilet paper you use at home, the RV paper is just a waste of money.
Show her how to use the toilet (how to add water and how to flush)
If it's just the two of you and it's just for the weekend advise her to use one bowl of water for peeing and two bowls of water for poop. It's not really necessary, but it does add extra water to the tank so it will drain out well at the end of the trip. If dry camping, use enough water to get the job done.
Tell her to leave a small amount of water in the bottom of the bowl after flushing to keep odors in the tank. Most toilets do this automatically but it doesn't hurt to tell her (and you)
Tell her to not run the vent fan for the few seconds while flushing. It will pull fumes (even your deodorizing fumes) up out of the tank.Turning the fan off or running it after using the bathroom will prevent this.
Tell her to put only body waste or toilet paper in the toilet. No hair, gum, sanitary napkins, etc. Some people like to say if you didn't eat it first it doesn't go in the toilet.
Oh if you happen to use the toilet and leave a skid mark or two, make sure you fill the bowl to cover the marks and let them sit for a while. Don't just let them sit and dry out on the side of the bowl.