Co sleep

Lydia
So my family is consisting of me, my fiance, a baby boy on the way, and his 6 year old daughter. Lately ive been feeling like everything is a issue with her and i. The current issue is the fact that she keeps asking to sleep in our bed. I dont want that. I believe that her bed is her bed and our bbed is our bed, i feel its unhealthy to develop a habit, and that she wins this stupid arguement if shes allowed. Also, im 30 weeks pregnant, extremely uncomfortable, i work at 5 in the morning and cant sleep half the time anyway, we sleep naked, and she flails around like crazy, but most of all its our space. We have a nighttime routine already set up and it seriously feels like an invasion. He doesnt see a problem with it and is not taking into account my feelings on the matter he wont listen. What i would like to know is all you ladies opinions on the matter, put yourself in my position and tell me what you would do. Because this is drivving me insane and i need input. Thanks.