I had the same problem. So I just started letting her win.
That's funny, on a scale I was told my 'competitive score' was infinitely high...so, I guess that means I would win against any and all opponents. (and don't even TRY that "infinity plus one" bogus oneupsmanship)
well if you wouldn't disagree, you would let them be right. When they are right, they would look at you differently. Think about it, all of us hate to be corrected :) and we waste energy, and our nerves when we argue.