There is a scene in 11/22/63 where Jake spots that Marena is pregnant, and he says that Al left it out of his notes completely.
He is rather shocked at this development, having not been informed of it by Al.
Later on, I think in chapter 27, when he is reading Al's final notes about the day of the shooting, there is a part where Al says
that "Marena gives birth in Parkland hospital to their 2nd child".
Was this a mistake in the book by Stephen King, contradicting himself? I was a bit confused by this...