OP went on DDs honeymoon with her and paid for IT. OP has focused on the cost twice, small fortune etc. OP does not explain why anyone thought this was a good idea or unusual or smothering. The information OP chooses to share reflects on her/her husband's financial generosity but not on their unusual choices to join in on their daughters honeymoon. Many people have queried why this happened, but OP chooses not to expand. (OP shares the info she wants to share).
People have asked if OP resents any financial gifts to her son. OP refuses to respond.
Many people have queried whether the daughter has explained her grievances and OP has dismissed them, had a mental block. The OP has not provided any further clarity.
OP speaks highly of her son, not her daughter.
OP stated she listened to her daughter moan, in order to shield her son in law from a side of her daughter that the OP perceives as unattractive. In the OP s mind she was trying to protect the relationship from her daughter's perceived negativity. If OP listens to the moaning, son-in-law doesn't have to. Why does OP do that? Why does she perceive it as her role to be a shield?
Is that a little weird? She is not listening with respect to her adult daughter, she is listening with the purpose of protecting her daughters marriage from an aspect of the daughter that OP ultimately doesn't approve of.
When the daughter asserted boundaries, the OP immediately circumvented them by communicating directly with the son in law.
OP are you anxious about your daughter relationship, are you projecting anxieties about communication styles and content onto your daughter s relationship?
Is it rude or unhelpful to position yourself as a barrier, to shield your son in law from your daughter's everyday venting? Do you think her role should be a happy clappy wife?
Perhaps your daughter was aware of your intention to act as a shield, and chose to cut you off. The shielding of the son in law, is quite demeaning to your daughter, and frankly (in my view) interfering in the normal development of their relationship.
Maybe she needs time and space to launch her married life. (without her mother monitoring her and projecting anxieties on to normal every day venting/nagging). The accompanying on the honeymoon seems like a really smothering and stunting thing to do.
Put yourself in your daughter's position, how would you have liked your parents to join you on honeymoon, and then resent paying for it. How would you have liked if your mother wanted to absorb a part of you that she perceived as negative/unattractive so you could present a version of yourself that your mother approved of to your new husband. You are telling your daughter, that part of herself is unattractive e (by doing this).