Hello, for detailed discussion, history and necessary treatment you can consult directly with me through practo.

Since the fractured bones are in contact, thr is very little chances of cross union. Continue plaster slab untill the swelling is present and then change to a cast. Maintain limb elevation untill the swelling persists. Kindly be in regular followup with your orthopedician

It should be treated conservatively. Kindly go to a ortho.surgeon near by.

Fracture on both bones of forearm at this age can be treated conservatively also with cast application for 4 to 6 weeks. Fracture doesn’t appear to grossly displaced so go for the casting.

It will heal without surgery and plaster but for few year there can be bump or deformity visible which children dont like it or parent dont like it. My opinion  Elastic  Nail (Tens nail) for both bones are good option then putting plate .  It will be there for 4-6 months and then can be removed. once good alingment and healing takes place. And seen on xrays