Single Dad

I've met people who as children experienced a similar situation to what Nadia is facing: raised by their mother who excluded the father, then lo and behold the child grows up and finds out that their dad wanted to be part of their life all along but their mum blocked him (either that or they just go on thinking their dad deserted them). It's heartbreaking and I don't want that for Nadia. 

 It doesn't matter who's right or wrong. I miss Nadia (as do my family) but it's Nadia herself who'll end up suffering most if this doesn't change - the possibility of a child growing up without knowing her father (and half of her family - part of her identity) is very sad. The fact that she has a dad here who loves her and wants to be there for her makes this so sad and unnecessary. Our personal feelings don't matter and we should be able to put them aside. Our options seem to be:

• Agreeing on Parental Responsibility and sticking to it. This is roughly based on these suggestions in an email I wrote last year - there's nothing unreasonable or out of the ordinary there. If you don't like anything in it then maybe you could just say and we could try to come to some agreement.
  
• Court. It is a last resort. I fear it would always leave bad feeling between the parents - and with Nadia in the middle it's not an optimistic scenario. 
  
• If it's a choice between the status quo and walking away completely then I have always felt that walking away would at least give Nadia some peace without her parents fighting all the time. The last 2 options seem to be a choice between the devil and the deep blue sea.

I'm open to any suggestions at all for moving forward.