I think I have been hiding under a rock...
Anyway, I was raised by a single father, and I think I turned out rather well (or I may be a bad example and be frightening you beyond belief).
That said, if this comes to a divorce, and I cannot say it will or it won't, I do not believe in joint custody arrangements. I would go for full custody, being willing to allow her generous visitation. I believe for legal reasons as well as parenting ones, there needs to be a final say.
I may fall outside of the general point of view, but I come from being brought up from young childhood in a single parent home. I truly believe a joint custodial arrangement is not capable of providing the stable environment a child needs.
The most important thing is that your daughter is in a stable loving environment.
