I do not know how to deal with my adult children. I have two girls in their forties. They were extremely jealous of each other as kids. In fact it seemed they hated each other. They were both very pretty. The oldest was very social and had lots of friends. The younger was not very social but smart. The older one gave me little trouble growing up. The younger was and still is a very angry spiteful person. We have a son that is nine years younger than the youngest girl.
We were very young parent (17 and 19) and tried to do the best we knew how. I know that I screamed too much and at times was physically abusive. I was raised that way also! My husband too. Our younger daughter reported us as abusive to the school. The police took her from us because my husband spanked her with a stick. (She was 16) upon investigation the authorities decided they wanted us to take her back. But also said we could not hit her. We could not do anything with her before and we could see right away that we couldn't now. We spoke with family and an aunt said she would try. She lived in a different town and our daughter might do better. She managed to stay with her for a year. She (our daughter)really wanted to get her education) and I think that helped a lot in her staying halfway in control.
During the summer before her senior year she came back to live with us. We lived in another town by then, before school started she ran off again. This time she called to say she was staying there. She was a couple of months from being 18 so we did not try to stop her. She got her self in trouble and came home and left several times after that. In the mean time our older daughter married had two children then had an affair and split her marriage up. Our son was pretty easy going as a child until he hit his teens. He tried drugs but straightened up and got a job and got married.
During all this time our middle daughter was pulling all kinds of stuff. Scamming boyfriends and fighting. But she managed to get a degree in criminal justice. She got a good job where she had access to people's info.She constantly harassed us.
Well she abused her access and ended up getting fired. We along with many other family and friends were notified our information had been broken into by an employee. (Her) she managed to get full retirement and benefits on the grounds of mental illness. She married had a child divorced. Apologized to us and promised not to act that way any longer. She moved home lived with us 1 year then moved out and it has all started again. She is jealous of any attention given to my sons child. The older daughter is too to a lessor degree. The middle wrote really nasty stuff to me on my Facebook. Then after being blocked sent threatening emails. I do believe she is sick but she keeps things so stirred up that even the other 2 are reacting. Sorry this is so long and it's only a small portion of this mess. I have felt like a failure as a parent for so long now I am just tired and worried about the grand kids.

You are enabling the bad one to do bad things. By letting her come home all the time. Sometimes the best love is tough love and let them fail and fall. Then if they really want to change, they can change.

You do not get involved between children, teach each one, upon their actions. You can always love them, just not help them or enable or accept their wrong doing

Just curious about what your husbands position in all this? At some point you have to lose the guilt and worry about grown kids, and grandchildren and focus on your own life which you probably have neglected far too long.

They are adults and will figure it out, or pay for their own actions. Difficult and emotional, as with most of us parents with grown kids, and grand kids is, but letting go and taking care of ourselves is the most important step we can take. Learn to love and support without kissing their booboo's any more because no doubt you are not getting any younger and have your own issues to deal with. Your own life to live.