Not to mention this:
Every so often, a similarity will strike and capture your breath. You'll see the shadow of the baby you once had in the baby you have now. You'll find yourself transported through time, once again the mother of your first child. The weather, or the noises, or the passage of time will strike you like a wet towel, and you'll return to the present. You'll realize that this baby is your second child, equally wonderful, but not the ghost baby of your memory.
You'll correct yourself when you call this baby by the wrong name, because the memories of the past are so sweet that just getting the words out is an achievement in itself.
You'll work hard to recreate this symmetry when you can--posing children in the same places, or in the same outfits, but it never matches the perfect, frightening serendipity of when you see your younger child do exactly what your older child did. At that moment, as if by magic, you will go back in time.