Look, you have told her that you are not opening for her at 7:15 and she is continuing to come early. This is disrespectful, and passive aggressive in my opinion. Like she is going to force you to open early by bumping it just a few minutes earlier each time. I would not open my door a second earlier than their contracted drop off. Disconnect your doorbell, shades drawn, lights out. Turn everything on, open the shades exactly at 7:30. If the Mom asks why you didn't hear her knocking, just say "Oh, well I open at 7:30 as you know. Surely you weren't knocking before I open because that would wake up my family and I find that very disrespectful. I'm sure you weren't doing that though, right?" I use my outside light to indicate that I am open for business. If it's not on, don't even think of knocking/ringing my bell. Same for the 5 to 10 lateness at night. "Thanks Dad, just make sure that you have your late payment of $7.00 (or whatever it is) in hand on drop off or I can't accept Junior tomorrow. Have a great night!" Don't make an issue about it, it's their problem. You ignore them in the morning and cash in at night until they either figure it out OR you get sick of it and get rid of them.