... "Will the king and I have children?" she asked.
"Oh, aye. Six-and-ten for him, and three for you."
The old woman was not done with her, however. "Gold shall be their crowns and gold their shrouds," she said. "And when your tears have drowned you, the valonqar shall wrap his hands about your pale white throat and choke the life from you."
I've always taken this to mean that our favorite golden haired queen will outlive all three of her children, though, I suppose, it could just imply two of them...
I refuse to accept that it could be Tyrion based mostly on my Cersei Is Always Wrong About Everything theorem. Jaime just makes so much narrative sense though, I'll be shocked if someone else does the deed.