Legal Question in Family Law in California

First, you must readjust your thinking that this is "visitation" time. It is his child sharing time during which he is responsible for the children. For example, you probably leave the children with someone when you are not available. It is not unusual that a significant other, parent, sibling or other person receive or drop off a child for child sharing times. All of that being said, whether the exchange is done by a third party, or even the child watched by a third party when a parent is not available would depend upon many different factors, including the relationship of the children to each parent and to the third party and the relationship of the parents to each other. So do not foreclose the idea but be prepared to discuss any significant detriment to the children. If the children know the girlfriend and the period between receiving the children and the time that Father will be home, there probably is no detriment and it is not an unreasonable request.

Likely ordered, unless there is some reason that such an arrangement would be detrimental to the children.