MIL deliver room drama

From the very beginning I have told EVERYONE that the only person in the room during delivery will be my husband. I am going to be in pain, and exposed, and the only person I want to drag through that torture is my husband.... his mother is an RN and thinks that this gives her some sort of pass into my delivery. She keeps telling me about other deliveries that she has been a part of and insinuating that the mother couldn't have made it through delivery without her guidance... 🤔. After again politely telling her that my SO will be the only one allowed in, she says, "Well I know my son, and I need to be there so that if he gets overwhelmed he can tap out and tag me in"...... um, fuck that. I don't get to "tap out" if I get overwhelmed so neither does he! I honestly don't plan on letting anyone know we are at the hospital until I am crowning. I seriously don't need to be worried about this, I just need to focus on my body and my baby. why is this so difficult for people to understand?