It seems like she should have given you a complete list of what to avoid...would have been less confusing for you.
Pure stevia extract has no sugar of any kind, but some brands of sweetener mix the stevia with either a sugar of some kind, or a sugar alcohol, to make it taste more like what we're used to.
I just looked on my box of Truvia, and it lists the ingredients as: "erythritol, rebiana, natural flavor". Erythritol is a sugar alcohol, rebiana is the stevia, and God only knows what "natural flavor" might be, although I'm sure you can rule out sugar of any type.
Anyway, from what you said you could have, I think Truvia would be ok. Good luck!