Battery draining fast

Actually, these old Chrysler systems are pretty simple once you understand them. What does them in today is age, rust and corrosion, people who don't understand them making wiring changes with quickie patch jobs to keep them running. Its what happens to 50 year old cars that go through multiple owners.

Also, ammeters have long ago disappeared from dash boards so few people understand them anymore.

I hope your daughter can hang in there a bit longer. This issue will get sorted out and she'll have a very nice, unique little car.