Wow what a difficult position, I can relate to the situation with your mother, thankful my MIL was keen to give us distance and happily came down the next morning (Felix was born at midnight)

My reasoning with my mother is that she makes a sterssfull siution wose, she had a lot of trauma with my birth and she would have made me feel worse, I decided that I would give a special job after the birth, that she would give Felix his first bath, she was hurt at the rejection, but thrilled at the offer of the first bath..DP was little put out that she was doing the first bath, but I explained how important it was to her and he could do everything else first with him..

DP called her down just before I started pushing and she arrived about an hour after he was born..DP's best friend & GF also came down, which I wouldn't have chosen, but in the end it was okay.. Mum immeadiately started freaking out about the blood and plecenta (she hemorraged after my birth)

I am glad you are being upfront now to your family, a first birth is a overwelming situtation because you are totally unsure how things will go for you..I say stick with YOUR wishes, your DP will realise how Labour is very much your domain and your wishes will be obayed by the midwives..you can tell them in advance you do not want his family there if you wish, he needs to realise that this is about your body and baby..not a sideshow for the family!