My wife and Daughter in law

Hello,
I don't know if I've posted this in the right section or if I'm actually allowed to be here as I'm actually a Grandad however I'm really struggling with who to turn too.
My wife and I have been married for nearly 50 years and have a adult son and a daughter. I love my wife very much and she has many good qualities however I am struggling to justify and supporr some of my wife's behaviour and have for a long time. My wife was a stay at home housewife which I believe was common for our generation and brought up our children who she dotes on and are her whole life. I have privately felt that at times my wife has interfered in the lives of our adult children previously however our daughter seems to appreciate her support and assistance with childcare and managing her house as her husband frequently works away and is very like my wife in many ways. My wife is very involved in the day to day lives of our daughters children as her husbands parents are no longer with us unfortunately and our daughter seems to struggle to manage on her own with the children and house or so my wife believes. My current daughter in law is my sons second wife. In hind sight I suspect that the actions and behaviour of my wife may have contributed to the breakdown of my sons first marriage by interfering in my sons life and her behaviour towards my ex daughter in law howver I am not privy to the full details. My wife has fallen out with a number of members of her own family and mine there always seems to be some drama or problems amongst her group of friends none of whom I find particularly nice people as they are very gossipy and entitled. My wife pretty much raised our children and they are her whole life, I appreciate that in some ways she has made a lot of sacrafices however she has no outside interests or hobbies which I feel is to her detriment. I am ashamed to say I find both my children to be spoilt and entitled. They both seem to rely or have been made to believe they have to rely on my wife to lead their day to day lives. My wife in turn seems to thrive on being needed and 'helping' them with basic day to day tasks. When my daughter had her children she seemed to struggle at first to adapt so my wife took over and provided a lot of practical and emotional support which although I'm sure my daughter found invaluable my wife also seemed to thrive and take pleasure in how much my daughter "struggled" and how much help she was.
My current daughter in law is a very intelligent but kind and caring woman and I believe she is very good for my son. She has a good job and is very independent and has many good qualities and clearly cares very much for my son and they have many interests in common and she is very supportive to him. My wife has taken a dislike to her from the start and I have been ashamed of her behaviour towards her at times. My daughter in law is naturally a quiet person and although at first I found it a little hard to make conversation with her my son advised this is just how she was and I have over time found her easier to talk too and get along with, she is always very polite and I have accepted her who she is. My wife took a dislike to her from first meeting her and both her amd my daughter have been hostile and unpleasant towards her. Over the years my daughter in law has gradually retreated further from us and refused to rise to my wife's verbal put downs and sharp tongue and attempts to create gossip which has infuriated my wife further who has gradually become nastier and more unpleasant towards my daughter in law. I am of the generation that believes that I should support my wife however I do not condone this behaviour. My wife blames my daughter in law for taking our son away from her and turning her against him however all I see is my son finally stepping away from his reliance on his mother and getting on with his life as a fully functioning adult however I do understand that this maybe hard for my wife.
My daughter in law and son had their first baby my grandson last year. My daughter law had a difficult birth and although I do not know the full details this ended in a emergency caesaerian after over a week in the induction ward and both mother and baby where unwell and hospitalised for several days afterwards, my son kept in contact with us however this was quite brief and he was understandably very stressed. My wife was furious that he did not involve her further and bombarded him with multiple aggressive phone calls and messages which I do not feel helped. Whilst my daughter in law was in hospital her much loved grandma on her mother's side unfortunately died and her mother was diagnosed with a type of aggressive cancer. My daughter in law has also lost 2 much loved pets due to what I belive was cancer one just before and one just after the birth of her son and I believe there where some issues with the standard of care both she and my grandson received in the hospital as there has been some investigations.
My wife was absolutely furious that she was not invited to the hospital to meet our new grandson or be present at the birth however I believe that due to covid restrictions this was not possible anyway however I have heard her telling her friend how she was prevented from doing so by our daughter in law. When we met our grandson a few days after they returned home my daughter in law was even quieter than usual and looked unwell however our grandson seemed content and well cared for. My wife felt very slighted that extended members of my daughter in laws family met the baby before some of our family like my daughter did however this was at my daughter in laws grandmother's funeral which I believe was delayed until my daughter in law and grandson where discharged from hospital. My daughter in law is close to her mum and devastated about the cancer diagnosis particularly the timing of which. My daughter in law has a medical background and had accompanied her mother on a lot of her hospital trips as well as looking after our grandson which my wife has seemed to resent as she believes that the other grandparents have been given priority. My wife has taken every opportunity to criticise the decisions our son and daughter in law have made about our grandson from what brands of equipment to advise. My daughter in law has breast fed our grandson, my wife didn't manage to breast feed our children and they where bottle fed which seems to make her very angry. My son generally sides with his mother and does not support his wife even though I believe from my research that my daughter in law is correct in some matters such as sleeping positions. My daughter in law has gradually retreated even further from us, she will generally accompany my son on visits however we do not see her or our grandson on their own without my son being present. My son recently spoke to my wife as he was concerned about my daughter in law may have post natal depression however im ashamed to say my wife used some of this information to suggest my daughter in law was a unfit mother and that my grandson was not being cared for which I do not believe to be the case although I maybe wrong. My wife plans to contact social services/ my daughter in law health visitor and doctor to suggest that her grandson is not being cared for and offer herself as support. My daughter in law has had a very hard time personally recently and I feel has coped well and I would love to assist my son to support her more. I am concerned that if my wife carries out her plan that my daughter in laws will find out and cut all contact and or leave my son. I want to address this with my wife and also that I feel that her behaviour towards our daughter in law is unkind and unsupportive however I do not know how to approach this with her. I have been so disgusted with her behaviour I have considered leaving her but we have been together many years and she also has many good qualities. Can anyone offer any advise.
Thanks