depends on how good a job you do and what quality bud you're using. I always make cookies instead of brownies but I've made them powerful enough where half of the cookie (standard sized cookie) was enough for everybody to be baked out of their mind for the next 3-4 hours or so... We sold a couple and failed to warn one guy who ate the whole thing and apparently was drooling on himself during the night. My rule of thumb is if you get high during the baking process, they're probably pretty good. You might want to suggest that your wife eases into it and eats half a brownie at a time, wait, see how it's hitting her, and then decide if she wants to eat more.

-edit- oh wait, 2 grams. You probably don't have anything to worry about but I'd still recommend easing into it.