This is a really bizarre set of sentences, and I think the best way of finding a correct answer is through process of elimination.
My baby-sister-dropped her nearly full bottle of juice in a mud puddle. Baby-sister-dropped is wrong here.
My baby sister dropped her nearly full bottle-of juice-in a mud puddle. Both of those are wrong, those words aren't even remotely meant to be grouped together.
My baby sister dropped her nearly full-bottle of juice-in a mud puddle. Juice-in is still wrong.
My baby sister dropped her bottle of juice in a mud-puddle. This is probably correct.
