Anyone surviving a multi-generational household?

Helpful suggestions on how this works for you will be welcome! My mother, 87 with undiagnosed mild dementia, has been living with me since fall. Adjustment has been OK with a few bumps, but generally good. Now, my adult daughter & 2 year old granddaughter will be moving in with me soon. I have the room, but it will disrupt the established routines. When they have visited, everything goes well & my mother enjoys their company & activity. However, I've noticed anxiety in her that comes out in extra neediness, edginess and says she should just be in a NH. I'm sure the uncertainty of the situation is stressful, as it is for me. I've tried to reassure her that she is still needed and loved by us all, but my stress is probably felt and worries her, too. She may not be able to express those feelings as easily as in the past and causes her to react in those other ways. I'm hoping once they are settled in things will calm down in her mind. Any problematic things to watch out for and suggestions for blending these diverse age groups will be welcome!