If by "meaning" you are asking what the person who originally created
Vanessa intended, I think
Jonathan Swift simply intended it to honor his friend
Esther Vanhomrigh, and so if it had a "meaning" it was just "beautiful nymph-like character in my poem honoring my friend
Esther."
Interpreting it as "from the stars" is to go beyond what Swift himself probably intended by joining together the original ancient derivations of
Esther and the
Dutch preposition "
Van". If one wants to do this it's fine, as long as one realizes you're putting an interpretation on the name that there's no evidence the original creator of the name intended it to have.