I found Jeff's Vol 2 on Relationships very helpful. In fact, I constructed a composite chart on myself and my wife and found it accurate. I wondered, however, about soul contracts between a parent and a child and wondered if a composite chart could be done between parent and child to examine the soul contract there. Would that work?
Yes, absolutely. Take the interpretations given in Pluto Vol 2, which are geared for intimate couples, and phrase the same principles in terms appropriate for parent-child relationships.
Another valuable thing to do is look at the synastry chart of parent-child and see how the parent is going to appear to the child, through the filter of the child's chart, and vice versa, how the child is going to appear to the parent, through the filter of the parent's chart. These can be very different than the way the parent and the child appear to themselves.