contact, not primary carer

I think she sees this as less time for her, it probably doesnt suit her life and what she has set up, so you have to think, what is the incentive for her to agree to this change? nothing, she is losing out.
Only route maybe court, or other option is as your daughter is 11, does she understand? at that age its borderline but she can have as much influence as anyone?
In court her wishes would be listened too I am sure.
Does she understand your new job and the situation?
Your ex is having her daughter for an extra weekend it changes the routine over a year, she may not want that because of what she does with new partner?

thanks for all this help and advice, think I will explore mediation and take it from there.
I am sure it doesnt have to be this difficult!