Surprisingly, there is no special name for a female goose. We'll tell you more: the term "goose" is always applied to the female in particular, while "gander", on the contrary, is applied to the male goose. Young birds before fledging are known as goslings. There is even a collective noun for a group of geese on the ground: a gaggle. When in flight, geese are called either a skein or a wedge; when flying close together, they are called a plump. So be careful, while choosing words!

More Info: en.wikipedia.org