My dd is 8, she goes to her dads every second weekend Friday - Monday. We used to do 50/50 shared so I would have her for 4 days then at her dads for 3 each week but that stopped at the end of 2019 due to his work commitments. They have always been very close, she has always been a daddy's girl and he is a wonderful father, I have no worries in that regard.
However, naturally, as for the past two years she's been spending much more time with me we have gotten closer (always been close but definitely more so now) and for the past 6 months she has started to show resistance going to her dads.
I have had many talks with her about this, she says there is nothing wrong at her dads house and she doesn't mind going to see him during the day but would rather stay at my house. She cries or argues when it's time to go to her dads, and gets very excited when she knows it's her weekend with me.
Once in a while she has phoned her dad and asked if she can stay at my house instead on one of his nights and when he's said yes, she cries because she feels like she is hurting her dads feeling.
So far I have dealt with it by saying that it's her weekend with her dad and that she will have a great time and be back home before she knows it. My mum on the other hand thinks it's cruel and she's 'getting to that age', I still think 8 is a bit too young to be making such big decisions.
And I'm not being funny but I would never get a break either if she didn't go!