She hasn't accompanied me yet on my visitation weekends. This weekend will be the first time that she will do so. She and I will both be going up to the apartment for my visitation. Based on my feelings, and on advice from here and other places, I haven't wanted to introduce her until my 3-year old has had time to adjust to the divorce situation.So you see the children at your old apartment and NOT at the home you share with your fiance? If that's the case, why is the girlfriend an issue at all?
Personally, I agree with you. There is no issue, only that my ex is making it an issue on the grounds that she doesn't know my fiancee, and therefore feels she has the right to deny my access to them.