“When my DP died we kept the money to be split between DD and DS to help them into a property each. Then the prices rocketed and DS met DIL so DH and DD asked if it was ok to take the money to help DD. She was on her own and we could only help one.”
So it was your daughter who connived with your husband to get all the inheritance from your parents for herself? And you think that was fair?
Are you also planning to protect your family money from any future husband of your daughters? As you know from her first divorce, all assets and savings are considered joint funds in a divorce and both parties are entitled to a share. However you try to protect your money to go only to blood relatives, you cannot do that in the event of a divorce. Even if I leave my money to my grandchildren, what’s to say they won’t get divorced in the future when their inheritance becomes part of their joint assets?
You ask for advice here yet totally ignore what everyone is suggesting. I think in your heart you know that your husband has been unfair to your son and now you can make amends.
Your daughter will never agree to share her inheritance with her brother, she got her hands on your money years ago and is not going to let it slip away now.
Go and talk to a solicitor experienced in wills on your own without your daughter and listen to the solicitor then follow his advice without telling your daughter until your will is sorted out. I find it hard to believe that your husband, who was so dismissive of your financial understanding, would consult with a female child over money. But it is time for you to act on your own now.