Adonis was a beautiful human youth Aphrodite loved. She took care of him as a baby and entrusted him to Persephone. Persephone also fell in love with Adonis, and the Goddesses argued over him. In the end Zeus overruled, stating that Adonis would spend a third of the year with Aphrodite, and third with Persephone, and a third to rest from the sexual demands of both Goddesses. Aphrodite used her magic girdle to make Adonis so in love with her that he chose to spend two thirds of the year with her. Persephone grew jealous, and arranged for Adonis to die in a boar hunt so he would be with her always. (there are other versions, the key points are: he was lover of both Aphrodite and Persephone, and was killed by a boar)
Aphrodite and Hermes:
Aphrodite was married to the smith-God Hephaistos. However, she loved Ares and continued an affair with him after their marriage. Hephaistos grew suspicious, and forged a fine net with which he trapped the two lovers in, in bed. He then called all the Gods to witness their shame. Hermes declared that he would happly switch places with Ares in the net, even if all the Goddesses were looking on too. Posiden took on to free them from the net by reassuring Hephaistos that he would re-pay him for the betrothan gifts. In gratitute, Aphrodite slept with Posiden, and bore him sons Rhodos and Herophilus. She also slept with Hermes, due to his gallant comment, and bore him Hermaphroditos, a two sexed being.
She was the Goddess of Love, she slept with a great many people. She slept with Dionysos and bore him Priapos (a drawfish man with a huge penis) - although some myths say the father was Adonis and some myths say the father was Zeus. She bore Ares: Harmonia, Deimos, and Phobos. And many more children.
And that's just her immortal lovers...
So, in conclusion, your friend has chosen to style herself after the Goddess of Love who - whilst beautiful - is not known for her fidelity. And she's styled her boyfriend as a handsome youth who also sleeps with her neice.
She's also displaying a remarkable lack of knowledge for the general fate of anyone who compares themselves to the Gods (Medusa, Arachne...)