It's normal to feel that way or have a particular bias especially when you are pregnant and hormonal. By the time the baby is here and you are holding that sweetbundle in your arms, I doubt you will care whether it's a boy or girl.
I have a little girl. She is the sweetest and I just love her to death. I'm also having another little girl soon. And I couldn't be happier expecially after how the first one turned out :)
Good luck and I hope you an embrace the fact that you are having a girl. And that you can give her the love she deserves.
You will get use to it your baby girl is goin to be like your best friend..
I think it's normal to feel how you feel.lol but I'm sure it'll change after she's here :)
Oh and finding a name that no one has is almost impossible unless you want to invent a name. There are tons of people in this world, just remember that.
Just be thankful you have a healthy baby growing inside you hun. So many mums to be with a difficulty pregnancy would love to be in your shoes. I kinda know how you feel, I have 5 younger brothers but I'm pregnant with a girl. I know I'll get a lil upset if I had a boy at first but I woulda got over it