Stock is a flavoured liquid preparation. It forms the basis of many dishes, particularly soups and sauces. Making stocks involves simmering animal bones or meat, seafood, or vegetables in water or wine, adding mirepoix or other aromatics for more flavour.
Whoopie pies are like the best parts of a cupcake squished into one delicious sandwich. That would be the top of the cupcake and the frosting, of course.
Babs Seed, being a cousin of Apple Bloom, is another one of Applejack's cousins. She has a sister named Sunflower. Another relative of Applejack's is Goldie Delicious, who lives in a cabin not far from Ponyville. She's mentioned and appears in the episode Pinkie Apple Pie.