You need to have a cable going to the VCR from your modulator thingy, I guess the box beside the DVD. The VCR should have an input that says cable in or antenna in, then you can put the VCR on channel 3 or 4 to see what is on the DVD, Good luck.
She mentioned that her setup is all older, and from the brief view I could get of it, im betting its a single rca connection. The only device I see thats got moderately new component standards is the DVD player. VCR is mono, TV is most likely single input rca with select for cable or antenna for channel programming, etc.