If you can read french, the Caesarion's birthdate has been dealt with by Didier Devauchelle in a paper : "La stèle du Sérapéum IM8 (Stela Louvre 335)et la question de la naissance de Césarion", Enchoria, 27, 2002. I'm trying to get a scan from my fellow egyptologists.

As an amateur egyptologist, I know Zahi Hawass and I think we must be very cautious about what he says, as long as the alleged tomb of Cleopatra has not been digged.

Concerning the other queen Caesar "loved", it was Eunoe, wife of the king Bogudes, according to Suetonius (Caesar 52,1) : " He had love affairs with queens too, including Eunoe the Moor, wife of Bogudes, on whom, as well as on her husband, he bestowed many splendid presents, as Naso writes."