In the morning of day 14, I stirred the starter, discarded half (around 4 ounces), and fed it 1/2 cup white-wheat flour and 1/4 cup filtered water, mixing it up so there was no dry flour left.
After two weeks, we were finally in business. By the afternoon, the starter had more that doubled (almost at the top of the jar) and was bubbly and smelling more yeast-y.