Are you concerned that your loved one with dementia will hurt a family member?

My mother was diagnosed with dementia in December 2019, though I have seen evidence of it since early 2016--just couldn't get her to a doctor to officially confirm it. Last week I took her to a routine appointment with her gastroenterologist and she commented on a still life that had a knife in it. She commented that it was a lovely sharp knife and that she needed something like that to kill her husband. I was, to say the least, crushed that she would talk about my father that way--especially since he tries so hard to be patient with her and take care of her. At first I thought it was just an off-the-cuff comment, but today my daughter called after visiting her and told me that my mom had angrily insisted that no one take the pair of scissors she has stashed on her bed. We have an appointment this month with a psychologist and her family doctor and I plan to discuss this with them. But, I was wondering have any of you had to deal with this in the past? Are these her true feelings that are now coming out as the filter is diminished?