I doubt, jogr, if your daughter-in-law's 'dislike' of you has anything to do with you personally,, what you have done or not done. There is a certain type of person who deliberately seeks out a spouse they can dominate, and in the case of a daughter-in -law, the mother -in-law is the first target to be disposed of. She will see you as an enemy simply because you have some influence with your son, and she cannot allow that.
I have two close friends both of whom welcomed their daughter-in-laws with open arms, did everything they could to help, particularly financially, and both were estranged from the family at the instigation of said daughter-in-law.
Both maintained very limited contact with their sons and grandchildren; one because son and wife are not at all ashamed to come begging for money 'for the grandchildren' and the only way she is allowed to see them is if she pays up; the other because of a family crisis when the son lost his job, as a result of wife's interference, had a breakdown, and she was needed for help and yes, more money. DIL had to go out to work for the first time in her life, at fifty.
All you can do is maintain contact and do not criticise the wife in any way. One son now realises how much damage his wife has caused, destroying his career and wider family, but will not leave until the last child has left home ; the other is still besotted with his wife, who tells their children that 'Grandma stole money from me which is why she had to leave our house' which they faithfully repeated to Grandma and asked her why she did it.
You are dealing with a woman who will stop at nothing to maintain control, so be as 'vanilla' as you can and hope you can develop a relationship with the grandchildren when they are adults and realise what has happened.