There is a lot of debate when it comes to nitrates and nitites but I believe these cures are necessary when low temperatures are involved.
I use a lot of bought seasonings, and when I cold smoke I use nitrites to help prevent botulism. Nitrites are natural and are found in higher levels in many vegetables or anything with nitrogen, and are also produced naturally by our bodies. Too much nitrites however can be a bad thing so proper measurement is important. I think the nitrite cure I use calls for 1/4 tsp per pound of meat, and this should be mixed with seasonings and water and mixed well into the meat.
If your wife eats hams, bacon, or hotdogs then she's had meat cured with nitrites/nitrates and she should be ok