I'm preparing a lecture on Cleopatra to be given just before the Ides (I'll be in Rome this very day and of course, I'll go to the temple of The Deified Julius and leave a flower there...) and it seems very difficult to distinguish mere gossip from historical information, especially if a woman's reputation is at stake (Cleo was an oriental queen and a powerfull personnality ; an unbearable combination of qualities for the old dinosaurs of the Senate !)

But concerning her statue, I think that the explanation is perhaps much less romantic than all that has been said by Cicero and his epigones : in Ancient Egypt, the statues of a king were often given the likeness of the dynastic god (mainly Amun during the New Kingdom), because the king was his living image (for instance, in ancient egyptian, the meaning of "Tut-Ankh-Amun" is "living image of Amun").

So, if Cleopatra had a statue a Venus/Isis made for her, it is likely that it looked like her because Cleopatra was REALLY the living image of Isis. It is not chocking for an egyptologist but for a man like Cicero, it was certainly :-) !