Hi SheriR, i agree with other replies. Stress can make dementia symptoms worse. Often people going back home, after being in a bad care home, can suddenly show a decrease in dementia symptoms as stress levels reduce. So the same would apply the other way round with increase in stress. Losing a partner/spouse after 70yrs is huge beyond understanding. She will feel she has lost half of herself. Someone once told me they felt they had lost their right arm after a bereavement. The physical pain attached to grief was huge. So it must be incredibly disorientating for your mum. Give her lots of hugs.
My mum slept in her bed with heavy blankets on my dads side. She said she couldnt sleep without him being next to her. So the blankets helped with the physical change, as well as the emotional changes. We forget how they miss touch, breathing sounds, warmth. You can get sound recordings of white noise to help with sleep. Some of these have breathing sounds which can be really calming. Water bottles, snuggle blankets, can all help to keep a person calm. If she gets a good night sleep that can help her during the daytime hours.
Music, poems, radio programmes can all help calm relatives after a bereavement. Some essential/aromatherapy oils can help with relaxation. Lavender is suppose to be good. I bought one of those scented neck pillows made from beans that can be put in the microwave to warm up. But be careful to wrap it in a blanket if you got one, as older skin is very tender to direct heat. Gentle warmth is very soothing. But bean neck pillows can ease tension in the neck and shoulders.
Weighted blankets can also help to calm anxieties in loads of people. They settle nerves and give a feeling of being close to someone.
For some people the worse part after grief is not having that touch anymore. So even having one of those really soft faux fur throws, cushion covers are wonderful to have on a persons knee, so they can touch it whilst they are sitting.
You could think about what your mum misses the most and think of something that can provide a similar feeling.
Talk about your dad. Bring out photos. Have lots of hugs if she feels they help. Holding hands. Just sitting and being quiet together. This will all help with her anxiety and stress. 70yrs is a lifetime. How amazing and so rare. You are both right at the start of grief. So much to have to cope with, do, organise etc so be kind to yourselves. You must both miss your dad so very much. X