i would set up an altar in her honor with things she would favour [example, a silver dish to represent the moon, a statue or picture of her, lunar water] if possible you can place it near a window that the moonlight can land on it. if you can find a chant, prayer, or ritual to cal to her, i would give it a try. otherwise, i would light some incense, leave an offering, and ask her to be present, explain who you are and why you wish to work with her, then meditate and wait for an answer. keep an open mind as this can take some time to receive a response and it could be in many ways, a voice, a feeling, a dream, seeing a symbol of hers repeatedly. i would also try and do something on each moon phase [or at the very least the full moon]
that link should help you get some ideas to start comunicating and working with her.