I don't understand this woman being a lunatic at all.
It's not normal, I've had the misfortune to be close to many people who have died in my family in the past couple of years, and in no cases were people behaving like this around any of the deaths or funerals.
If someone had spoken to me like that in a hospice, gone to the GP, reported me to social services, whilst I was in the midst of caring for a terminally ill person and my husband had cancer, I just can't imagine what my reaction would be.
This woman is not only not being kind, she's actively malicious and ill-intentioned (whether through MH issues, dementia, personality disorder) and causing chaos- the Gp, social service and hospice staff and then the funeral staff all then have to waste time on her with her unjustified complaints- there's no evidence to support her claims whatsoever.
I would not only block her with one last text saying do not contact me again, I would report her if she continued that behaviour, to the hospice, funeral staff and so forth, and ultimately with the police if she kept it up. She is harassing you! I would tell her that as well.
Grief does not make you do these things, I sometimes wonder if people who say that have ever lost a close relative or the love of their life, it's not a thing! Grief might make you a bit grumpy, or depressed, or not yourself, but normally grief doesn't send you to start reporting relatives to social services unless you were the kind of person who did that already or it's triggered some type of nervous breakdown. Either way, it doesn't need to be indulged and it doesn't need kindness.
Be kind to yourself OP.