It is, and it's not impossible there was some, but we have pretty decent records of her ancestry, we know the Ptolemys were shocked by the idea of intermarrying with the local population, and we have busts and paintings and coin profiles of her, so we have evidence of what she looked like as well as pretty much anyone from that era.

You can see several of these here.

https://en.wikipedia.org/wiki/Cleopatra