The star alone is a bit scanty for identification, but it is strongly probable that this lady is related to other figures representing Hope for someone at sea, the star being Polaris. See:
Hi - the star means this lady is a Greek goddess from Greek mythology - there were lots of Gods and Goddess in the Greek Parthenon. As there is no other iconography to give us further clues on her identification just a single star it simply indicates the lady on the cameo is an Ancient Greek Goddess. That's all we can say.
You can find more details about the deities in Greek mythology at the following link which details the iconography associated with each of the deities.
http://www.theoi.com/Pantheon.html
You might be interested to know, that not everyone believes the gods and goddess's were in fact " myths". One of the few scholars able to read and interpret ancient Sumerian and Akkadian clay tablets, was Zecharia Sitchin (1920-2010), he wrote books on the subject and claimed the people actually physically existed. The following link takes you to Sitchin's website. http://www.sitchin.com