@john74,
I think you have to be tough - I know you don't want to do anything in front of your daughter to upset her - you might have to go to court and insist that you get your time.
I think in this case, you should have a go between to drop your daughter off or to hand off in a sense to you. It appears the mom is not being helpful and just making things worse for your daughter. A mom that cares enough to want the best for their child would be cooperative with this.
It isn't right for you or your daughter and unfortunately sometimes you have to be tough and fight to get what is right and best.