Baby girl bedding is generally designed to be gender-specific. That is, usually baby girl bedding will be pink, or feature a theme more commonly thought of as interesting to little girls, such as horses or fairies. Often baby girl bedding is princess-themed—and sometimes the beds themselves feature a very ornate design meant to convey the feeling of being a princess to the little girl.
If princesses aren't your thing, sometimes hot pink designs are a little more edgy, coming in zebra print. As always, most of these bedding options are available in bed sets, in which matching accessories come included.
And, of course, there are bedding designs for girls that do not use the color pink at all, nor provide a princess theme. There is no reason nautical or aviation-themed bedding could not be of potential interest for a girl. It is just up to her personality as well as your preference and how you want the room and bed to look.