Is it normal for a fetus to have cravings?

It's been proven that the human body knows what it needs better than you do. Often, when you crave foods, they have something you need.
A young boy used to eat almost nothing but salt. Upon being institutionalized and being refused salt, he dies. Why? An autopsy revealed his body was missing natural levels of sodium to make the body work. He naturally fixed this before he could talk by eating massive amounts of salt.
A study of preschoolers left to their own devices regarding food showed similar findings. The children we left to play with snacks scattered around the room for them to forage on their own. There were sweets, veggies, meats, fruits. Everything. Initially the kids started with the sweets (duh) but with in three days they automatically adjusted their meals to a fully balanced diet.
So maybe the fetus doesn't "crave" coffee, but the high calcium milk often found in high doses in fancy coffee these days. It's probably just an ingredient that she doesn't get enough of now that her demands have risen since becoming pregnant.