HELP ME!!!

Okay so I have been planning my birth and I want to have my partner and my mum in the room.

But my mother in law thinks she is coming in while I give birth and I don’t feel comfortable at all with that.

I did try to explain it to my partner but he thinks if my mum is there then why can’t his ..... I tried to explain that when his sister has a baby that’s when his mum will be there, but because it’s me giving birth I just feel comfortable with my mum and partner.

How will I talk to his mum and explain it ? i need some advice on what to say with our hurting her feelings.