They should always inform next of kin some are excellent at doing so, others are not. Children's families are always informed if they have a fall, all vulnerable people should have the same rights in my opinion.
If you haven't been told I suggest that you have it written in the notes (ask the manager) that you want to be informed! Some need telling what to do!
My mum had a fall last week and hurt her hip. If my dad hadn't habe been going to see her then he wouldn't have found out. She told him herself and they confirmed it! When I called to see how she was that night, the deputy manager said 'How did you find out'
My Dad's care home are excellent in this regard and always ring even if the incident is relatively minor. The home my Mam was in were less efficient and I once went in to visit and found Mam with a black eye and a nasty gash. It depends. X