I suggest that he put everything in writing, and keeps screen shots of texts.
His aim is to sound reasonable, while still protecting child.
So a suggestion would be a letter along the lines of:
I am willing for you to begin to make cnotact, but this needs to be done in a careful slow and sensitive way. How about
- a letter and a photo
- a short visit in a neutral setting eg playground
- one visit per week of about half an hour until relationship has developed and then see
I would also say that he does not want her to try and hug or pick up the dd, as she is a stranger, and that interactions must be at the dd's comfort level, so if she gets distressed, they will leave
Courts are very keen to see that you have been accommodating and reasonable.
Also in his letter, he needs to say that if she wants more, she will need to apply to court as he has full custody.
I recommend that he always has a third party with him as witness when they meet.
BUT he does need to try and make this work. So he needs to prepare dd for meeting her, and encourage dd to become friends with her.