Should I tell my Mom who has advanced Alzheimer's that my dad recently passed?

My 91 year old Mom is confined to bed in a nursing home and has advanced Alzheimer's disease. When my Dad recently passed my brothers and I decided not to tell Mom after consulting with several professionals. She would not have been able to attend the funeral. She was confused when he was brought to her by medical transport the night before he passed according to his wishes. She thought he was her father. Now I am wondering if this was the right decision and also concerned that if I do tell her would will push her over the edge.