She has probably never been outside. I would take her out there in your arms, and sit with her for a while, don't let her down because she'll feel all alone. Give her some time to get used to the sights and smells of the outdoors and it will probably help you two bond a bit more. If she realizes you are there to protect her she will learn to trust you even more. I would also say "outside" to her everytime you take her out so she will begin to recognize that word and help her training go further too. She'll learn that word and connect it with going outside. After she gets a little more comfortable sitting with you then let her down by your feet and hopefully she'll start going potty out there. To speed things along you could put her in the same spot as where she could smell her own 'bathroom' scent and she'll connect that faster with going potty. (You could actually leave a poo-poo of hers out there so she'll recognize that smell)
Good Luck, she'll come around.
P.S. Training gets easier and easier if you can teach her walk out the door by herself rather than carry her, but worry about that after she gets more comfortable with the outdoors. I have read that the biggest problem with training such small dogs has a lot to do with the owner carrying them out rather than letting them walk themselves outside.