Answer: The two squirrels ---> Noun phrase
To my sister ------> Not a noun phrase
All styles of dance ----> Noun phrase
My water ----> Noun phrase
Explanation: A noun phrase is a group of words that has a noun or an indefinite pronoun as its head. It can also include premodifiers and/or postmodifiers. Moreover, in most cases, a noun phrase can be replaced with a single pronoun. "The two squirrels", "all styles of dance" and "my water" are all noun phrases because they have nouns as heads ("squirrels", "styles" and "water" respectively). Furthermore, the three of them have been premodified, but only "the two squirrels" and "all styles of dance" have been postmodified. They can also be replaced with a single pronoun: "they" instead of "the two squirrels", "them" in place of "all styles of dance" and "it" instead of "my water".