I like Lysandra, there's many different aspects that can be pulled from it- the Greek original, the butterfly, or just as a variant of Alexandra. Lyra can be a nickname, which adds the astrology meaning.
I really like this name; it sounds so fresh and new, but whilst also having a lot of history about it. And it beats Alexandra any day of the week, in my opinion. :)
Lysandra was the daughter of Ptolemy I and Eurydice. She became Queen of Macedon in the 3rd century BCE after marrying Alexander V. After Alexander was murdered, she married Agathocles, who she had at least two children with. When Agathocles was executed, Lysandra fled to the court of Seleucus I with her children.