Corn is too fattening to give to her. Please take heed of other comments to your post. She will do much better if fed actual" chicken feed" product without "extras," dumped in.
Hello Henriette and welcome to BYC, You found an Amazing Poultry Community to be a part of with many great knowledgeable members, who are more then willing to jump in and help you along your journey with any questions you may have.
Hi Henriette, welcome to BYC! I agree with everyone, a good chicken feed is best. Corn is just a filler. She likely needs more protein. Until you go to the coop, you could feed her some fish, such as tuna or sardines.
Good luck with your sweet pet! Please remember that even if she doesn't live a long life, you are giving her a great one.