n the sentence, "in" is a prepositional phrase, but you have to add the words "place of" along. Otherwise it would not count as a prepositional phrase.
"Andrew says this because he had been able to keep his promise given to Joe Morgan; he had been able to save Mrs. Morgan as well as his newly born baby after it had been born lifeless. It means Andrew felt contented and jubilant at his own efforts and the achievement."
