My partners daughter hates me :(

I have been dating my partner for 2 and a half months and our relationship has been great. However his 10 year old daughter is not coping very well with the idea of her dad having a girlfriend. We live together however his daughter lives with her mum and comes to stay over every weekend. He cannot touch me or sit next to me, hug/kiss you name it, when she is around otherwise she runs off crying and sooking. She throws temper tantrums in public. If he calls me honey or babe she starts getting all emotional and stays like that the whole day. Now he is very distant from me whenever we are all together as he fears she will throw another tantrum. He has not had a girlfriend for years so it was always been those two but now that I'm in the picture things have become so difficult for everyone. 
I don't have children and I don't have a lot of patience like he does and I don't know what to do. I don't want all of this to put strain on our relationship. I don't want her to hate me either. I have tried to spend girly time with her and reassure her that nothing is going to change except we will all be doing fun things together but it hasn't really worked.
Mainly just venting but if anyone's been in a similar situation and has some advice that would be much appreciated. :(