Cradled in her mother's arms, the baby was sleeping.
A participial phrase is made up for a participle (a verb ending in–ing, ed or past participle form), and it fulfills the function of and adjective; that is to say, it modifies a noun. In the sentence, the noun that the participle phrase modifies is “baby”.
Answer:
Cradled in her mother's arms, the baby slept.
Participle phrase: cradled in her mother's arms.
Participle: cradled.
Noun modified: baby.
