Is it a Boy or Girl?

So tomorrow is the big day, Ultrasound DAY!... Is it a boy or a girl. Everyone in my family and all of my friends think it is a boy... but my daughter is the ONLY one who thinks it's a girl. I tend to think it will be a girl because of family history but we are rooting for a little mama's boy. If someone refers to it as her little brother or a boy, she quickly corrects them and say no it's my baby sister and her name is going to be Hannah Montana. I just want to say NO it is not, if it's a girl we will probably name her Sophie (no middle name picked out yet). Wish me luck and I will post on here what it is as soon as I get home.