Dart headliner

Hey guys it’s been a little since my daughter and I worked on her car, today was nice so we replaced some heater lines and cleaned up the engine bay. We are going to try to attack the headliner next before we get to the seats. So I’ve done some reading and it seems like the front and rear glass should really come out, we were trying to keep the cost as low as possible as I would like her to try to pay for as much of it as she can on her own. So when we got the car the back portion of the headliner was gone with just fiberglass above kinda up kinda hanging the front is mostly intact with a few tears. So first question should/does the glass need to come out. second what would be more human friendly than Fiberglas maybe ajuke of some sort and how thick I was thinking maybe 1/2”? Third can anyone verify how many bows should be in her car there are currently 4,the car is a 1972 Dodge Dart custom 4 dr. And lastly does any insulation or cardboard/ thin wood go over the sails in the back or does the fabric just get glued around the edges right over the holes. Thanks so much you guys for any help because some of the headliner is already out so I can’t see how it was done.