1)ask the hospital when u can take it back. I would expect in a few weeks, depending on how busy they are.
2)99 should show up unless she does not want to. Only parents don't attend kid's funeral. No rule against ex-wife
3.does 62 have any other relative? If no brothers/sisters, then his sons should take the responsibility up. More so if 62 left them money. Church will not do it unless u give them money to rent the hall, the burial spot etc etc. They can give a mass at church for a small donation of a few hundred dollars. Contact the priest at church
4.better keep your mouth shut as your 62 must have caused them deep hurt