Is it natural to have specific likings for certain foods?

yes it is very natural for a women to develop carvings for certain kinds of food. however, some women may not experience such a craving at all.either case it is normal

Most common craving are for pickles, ice cream.chocolate,cakes,sweets, spicy food etc.
also some women may have carving for things which are generally not eaten like chalk,mud,pencil lead,
ash etc. It is absolutely normal to develop such carving but make sure you don't eat such things :)