There is only one line. This is where your wife is correct. The one that sounds correct is the one considered correct. But, it is not. In that example, it is not even debatable as "is" is a being verb. And, a being very always takes a subject.
I will tell you one thing that is scary. And, this goes back 18 years. I always ask my patients how they are doing in school. Always. I ask, "How are you doing in school? And, they will invariably say, good. ALWAYS. Not one kid whether elementary, middle or high school has said, well. I will have to remember to ask my one patient who made it to the Scripps' National Spelling Bee. I would imagine she will say well.
