I am sorry you find yourself in this position. Like you, I would be feeling anxious about it but would know that it is your d's decision. I am very fortunate that my children were both very adamant that they wanted nothing to do with ow and H recognised this and didn't offer situations that involved both parties.
I understand your insecurity flaring about d's possible attachment to ow but as you've already recognised you and D have a wonderfully close relationship and although she's still young she's smart enough to know that unconditional love and support come from you. She wouldn't think of sacrificing that! Our children are sensitive and intuitive.
Talk this over with D and get her take on the situation.