Answer: False.
Step-by-step explanation: a participle is a word formed from a verb and used as an adjective, a noun, or to make compound verb forms. A participial phrase is a group of words containing a participle and modifiers that acts as an adjective. In the given sentence we can see an example of a participle in the word "grinning" which is acting as an adjective that modifies the noun "baby," but because it is only one word, it is not a participial phrase.