I'm going to kick my sister out of our small game development team
That feels drastic. Why do you need to remove her from your development team?
I don't like the way she is always taking over the group.
I know that you don't want to feel like you are being controlled, but kicking your sister out of the development group is not the answer. Sit down with the whole group and talk to your sister about her behavior.
I'm going to kick her out and create a new team with just people I like.
If you are going to create a new team anyway, I do not think that it is necessary for her to be kicked as you will be on a different team anyway. Try to have her strive with her work and if you will create a new group, I am sure that you will strive too.