Why does Venus disguise herself to Aeneas in book one of the Aeneid?

This is down to how you interperate it.

If you look at their differences, she is immortal and he mortal so they don't have a great family connection.

She disguises herself to get important infomation to her son about Libya and Dido whilst evading the need to stay any longer.

Also, it is important to note that her disguise is that of a Spartan girl. The description given to the Roman audience is that of a sexually provocative nature at the time so why would she want to do it if Aeneas is her son?