Perspective and relationships

My child is 10. She tried to tell me the other week that she's almost 12. I told her that she's 10. Later in the same discussion she informed me that she's almost 11. I informed her that she's not even 10 1/2 yet and she's still too young. The discussion was about why her mom and I split up. In my opinion, she's too young for me to explain why her mother and I split up. Her mother obviously doesn't agree so she's been told (in her perspective) that the divorce is all my fault. I keep telling my child that she doesn't have the perspective to understand the whys of what happens in an adult relationship. I'm not totally sure some adults do. To highlight that, I fall back on a situation that we experienced last summer. She met a girl whos older sister didn't move to Texas with the rest of the family. From her perspective, it was a fight with her mom over toast that did it. Deirdre understands that there is something wrong with that perspective. I want my child to grow up. I am pushing things a little bit and trying to teach her, but I also try to realized the limitations (my perspective) of the 10 y/o mentality. It appears to me that her mother is using her as a friend and venting emotions. I don't think this is appropriate. I will not speak ill of her mother to her. The most I will tell her is that I don't agree with her mother and what she sees is her perspective. I'm not sure Deirdre understands that but it'll have to do. I have promised Deirdre that I would explain my side of the story when I feel she's old enough. I don't know when that will be. I've thought about writing it all out in a letter to give to her in a couple years. It'll be about listening, and values, and the roles we are responsible for playing as both a parent and a spouse. Yes, I screwed up too. I guess I'm fortunate enough that Deirdre is trying to reconcile what she sees vs what she's told. And it's not working. So, she askes questions and I get to teach her to listen. In the end, hers and my relationship is getting better, and I really couldn't ask for too much more. Tom