Joint custody

I have been divorced from my ex-wife for 6 years now and she currently has primary custody of our 11 year old daughter. When I left, my ex-wife stayed in the house because I thought it was best to not uproot our child who at the time was 5. I am now in a better place financially than I was when I left. I am now in a house and getting married in a couple of weeks. There are no concerns of “fit parenting” involved in this, but I would like to file for joint custody now since I am in a different position. If I pursue this, is there only a chance of joint custody if her mother was unfit? What are the chances of a judge allowing joint custody now? Also, I know that if it was up to my child (which I know it’s not) she would want to be with me. At what age is a judge willing to talk to the child? I understand this is not a determining factor, but unsure about when the courts would listen to her.

One parent does not have to be unfit for the other to assume shared physical custody.
Whether or not the child will have a chance to be heard in the matter is not dependant on the child’s age, but rather the child maturity level.