Gender disappointment feel guilty

I found out I was having a girl recently and I was a little disappointed as I wanted a boy; but then I came to accept it and started to love the idea of a little princess. However, today I spent some time with my partners 5 year old niece and it totally put me off wanting a girl. She was a total brat! Whining, moaning, crying, screaming, demanding and manipulative. All the while she was like this I was looking at my bump and thinking "I do not want a daughter like this" most little boys I know are adorable and loving. I want to know how I Can bond with my bump and not think about my daughter acting like a brat just like his niece? I really want I love and bond with my bump but that brat just totally put me off. I'm scared there will be no bond when she's born. Help!