That sure made me look between my Pebble's legs. Mine is a boy and his danglers are between the anus and the urethral opening. I would say it's a girl. Although I'd wait for a more experienced one to confirm.
Why do you have a week-old kitty? Do you have her mama, too? Raising orphans is hard, do you know how to do everything? Www.kitten-rescue.com is a good site to help with that.