Some of these replies are comical and not what the OP is asking. Thinking its wonderful to have your adult child as well as your grandchildren living at your home is more often not as fun as you think. Its actually one of the most stressful times I've experienced and continue to experience. For the person commenting about getting them an apartment...lol. Sorry but the average and often times above average income earner can't afford multiple residences and IF we could do that, what makes you think we would or should? Does that teach them anything other than how to further take advantage of you? The only lesson there is, "I can live for free and continue to do nothing, except now I won't be judged for doing it in the presence of somebody else."
To the OP I feel your pain. My child does not clean, cook, stays in their pajamas all day watching TV and playing on their phone while their child runs around the house. When its your home and your children you have no problem cleaning, cooking etc.....that's the expectation. But when its your adult child and their child.....that is not the same. I feel you catlover, if feels like there is no end in sight and I'm 3 years into this. My marriage is falling apart because my spouse continues to side with our adult child and expects me to pick up all the unfulfilled chores because I work from home. We had problems before this but they are only MAGNIFIED NOW.
I have no good answers except....there are others out there and we are just as confused, angry, depressed, life on hold, etc. I have sat with my child on numerous occasions to lay out a plan, only for it to be pushed aside in 1 day. Every time I broach the subject, it becomes a "you" thing, "I will never live up to your expectations", "I'll never be good enough in your eyes", etc. I could name a hundred interactions like this. I hope the person that reads this, especially if its a child understands how destructive this can be for the parent and stops that behavior. I'm one conversation away from throwing in the towel and walking away from everything. I love my family but this is no way to live a happy productive life in the end. I am too old and tired to keep doing this. I just want peace and happiness in my life, not chaos and bad behaviors from my family.